De-speckling in optical measurement systems

Abstract

The present disclosure relates to despeckling in optical measurement systems. Embodiments relate to optical measurement systems that utilize multiple emitters to emit light during a measurement, and methods of performing measurements using these optical measurement systems. The optical measurement systems can include a light generation assembly configured to generate light via a light source unit, and a photonic integrated circuit including an emission group having a plurality of emitters. Each of the emitters is optically coupled to the light generation assembly to receive light generated from the light generation assembly, and can emit the light from a surface of the photonic integrated circuit. The optical measurement systems can perform a measurement in which the light generation assembly generates light and each of the plurality of emitters simultaneously emits the light received from the light generation assembly.

Description

[0001] Cross-references to related applications

[0002] This application is a non-provisional application of U.S. Provisional Patent Application No. 63 / 409,538, filed September 23, 2022, and U.S. Provisional Patent Application No. 63 / 461,777, filed April 25, 2023, and claims the benefit of both U.S. Provisional Patent Applications pursuant to 35 U.S.SC §119(e), the contents of which are incorporated herein by reference as fully disclosed herein. Technical Field

[0003] The described embodiments generally relate to an optical measurement system that utilizes multiple emitters to generate light during measurement. More specifically, the embodiments include an optical measurement system capable of selectively adjusting the phase of light emitted from multiple emitters during measurement to reduce coherence noise. Background Technology

[0004] Optical measurement systems can be used to identify the presence, type, and / or one or more properties of objects or substances in the environment surrounding the optical measurement system. Depending on what the optical measurement system is measuring (e.g., the type or property of the sample being measured), the signal-to-noise ratio (“SNR”) of a single measurement may be limited by different noise sources. For example, coherent noise sources such as speckle noise may limit the SNR in many cases. Therefore, it may be desirable to configure the optical measurement system to reduce the amount of noise present in the measurements performed by the optical measurement system. Summary of the Invention

[0005] Implementations relate to optical measurement systems that utilize multiple emitters to emit light during measurement, and methods for performing measurements using these optical measurement systems. In some implementations, an optical measurement system includes a light generating component having a light source unit configured to generate light. The optical measurement system also includes a photonic integrated circuit having an emission group. The emission group includes multiple emitters optically coupled to the light generating component to receive light generated by the light generating component. The optical measurement system further includes a detector group; and a controller configured to perform measurements using the light generating component, the emission group, and the detector group.

[0006] In some embodiments, the measurement includes: using the light source unit to generate light; and simultaneously emitting the generated light from each of the plurality of emitters, such that the plurality of emitters emit light in a set of corresponding phase states defined by a measurement state. The measurement also includes changing the measurement state between a plurality of target measurement states having a common phase state distribution during the simultaneous emission of the generated light. The measurement further includes using a detector array to measure returned light received during the simultaneous emission of the generated emitted light, such that during the measurement period, the plurality of emitters emit light only in measurement states having a common phase state distribution.

[0007] In some of these variations, the emission group is a first emission group, and the photonic integrated circuit includes multiple emission groups, each of which is optically coupled to the light-generating component to receive light generated by the light-generating component. Similarly, the detector group may be a first detector group, and the optical measurement system includes multiple detector groups, each including the first detector group. In some of these variations, the measurement is a first measurement, and the controller is configured to perform a second measurement using the light-generating component, a second emission group from the multiple emission groups, and a second detector group from the multiple detector groups. In some of these variations, the controller is configured to perform the first measurement simultaneously with the second measurement.

[0008] Additionally or alternatively, the photonic integrated circuit may include a phase shifter array having a plurality of phase shifters, such that each of the plurality of phase shifters is controllable to change the phase state of light emitted by a corresponding emitter among the plurality of emitters. In these variations, the controller is configured to control the phase shifter array during the measurement to adjust the relative phase states of the plurality of emitters, such that the plurality of emitters emit light with the corresponding set of phase states for each of the plurality of target measurement states. In some of these variations, the optical measurement system may include a driver configured to control the phase state of each of the plurality of phase shifters.

[0009] In some variations, the driver includes multiple switch-shifter pairs connected in series to a power supply. Each switch-shifter pair includes a corresponding phase shifter among the multiple phase shifters; and a switch connected in parallel with the corresponding phase shifter among the multiple phase shifters. In other variations, the driver includes multiple controllable current sources connected in parallel to a power supply, such that each controllable current source is connected in series with a corresponding phase shifter among the multiple phase shifters.

[0010] In some variations, the light-generating component includes a switching network that optically couples the light source unit to the plurality of emitters. Additionally or alternatively, the optical measurement system may include an interposer on which the photonic integrated circuit and the plurality of detector groups are mounted. In some variations, each phase of the plurality of target measurement states is selected from a binary candidate phase state pair.

[0011] Other embodiments relate to an optical measurement system including a light generating assembly having a light source unit configured to generate light, a controller, and a photonic integrated circuit including an emitter group and a phase shifter array. The optical measurement system can be configured such that the emitter includes a plurality of emitters, each of which is optically coupled to the light generating assembly to receive light generated by the light generating assembly and emit a corresponding beam. Similarly, the phase shifter array includes a plurality of phase shifters, such that each of the phase shifters is controllable to set the phase state of the beam emitted by a corresponding emitter among the plurality of emitters.

[0012] The controller is configured to control the light-generating component to generate light, such that the plurality of emitters simultaneously emit light from the photonic integrated circuit. The controller also controls the phase shifter array while the plurality of emitters simultaneously emit light, causing the measurement states of the plurality of emitters to repeatedly cycle between a plurality of target measurement states, such that each of the plurality of target measurement states has a common phase distribution. The optical measurement system may also include a detector array, wherein the controller is configured to use the detector array to measure the returned light received when the plurality of emitters simultaneously emit light. In some of these variations, the optical measurement system includes an interposer layer, wherein the photonic integrated circuit and the plurality of detector arrays are mounted on the interposer layer.

[0013] Additionally or alternatively, the optical measurement system includes a driver configured to control the phase state of each of the plurality of phase shifters. In some variations, the driver controls the phase state of each of the plurality of phase shifters based on a phase encoding matrix. Additionally or alternatively, the driver includes a plurality of switch-shifter pairs connected in series to a power supply. In these variations, each of the plurality of switch-shifter pairs includes: a corresponding phase shifter among the plurality of phase shifters; and a switch connected in parallel with the corresponding phase shifter among the plurality of phase shifters. In other variations, the driver includes a plurality of controllable current sources connected in parallel to a power supply, such that each of the controllable current sources is connected in series to a corresponding phase shifter among the plurality of phase shifters.

[0014] Additionally or alternatively, the light-generating component may include a switching network optically coupling the light source unit to the plurality of emitters. In some variations, each phase of a plurality of target measurement states is selected from a binary candidate phase state pair. Additionally or alternatively, the plurality of target measurement states may be a first plurality of target measurement states, the common phase state distribution may be a first common phase state distribution, and the controller may be configured to control the phase shifter array to repeatedly cycle the measurement states of the plurality of emitters between a second plurality of target measurement states when the plurality of emitters simultaneously emit light. In these cases, the second plurality of target measurement states have a second common phase state distribution different from the first phase state distribution.

[0015] Other embodiments relate to a method of performing measurements using an optical measurement system. This method may include: simultaneously emitting light from multiple emitters of an emission group of a photonic integrated circuit; and performing a measurement sequence including a first measurement phase and a second measurement phase. Performing the first measurement phase may include controlling a phase shifter array to perform at least one first iteration while the multiple emitters simultaneously emit light, in which the measurement states of the multiple emitters change between a first plurality of target measurement states having a first common phase state distribution. The first measurement phase also includes using a detector array to measure returned light received during the at least one first iteration.

[0016] Similarly, the second measurement phase includes controlling the phase shifter array to perform at least one second iteration while the plurality of transmitters simultaneously emit light, in which the measurement state of the plurality of transmitters changes between a second plurality of target measurement states having a second common phase distribution different from the first common phase distribution. The second measurement phase also includes using the detector array to measure the returned light received during the at least one second iteration.

[0017] In some of these variations, performing the first measurement phase includes performing multiple first iterations. Additionally or alternatively, performing the second measurement phase includes performing multiple second iterations. Additionally or alternatively, the method may include repeating the measurement sequence. In some of these variations, repeating the measurement sequence includes changing the order of the first and second measurement phases.

[0018] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent from the accompanying drawings and by studying the following description. Attached Figure Description

[0019] This disclosure will be readily understood from the following detailed description taken in conjunction with the accompanying drawings, wherein similar reference numerals denote similar structural elements, and wherein:

[0020] Figure 1A A partial cross-sectional side view of a device incorporating an optical measurement system as described herein is shown. Figure 1B It shows Figure 1A A top view of the device.

[0021] Figure 2 A schematic diagram of a variation of the optical measurement system as described herein is shown.

[0022] Figure 3 A schematic diagram of a portion of an optical measurement system with a transmitter group and a phase shifter array is shown, the transmitter group having multiple transmitters.

[0023] Figure 4A and Figure 4B An exemplary phase encoding matrix that can be used with the optical measurement system described herein is depicted.

[0024] Figure 5A and Figure 5B A schematic diagram of a driver for controlling a phase shifter array, as described herein, is shown.

[0025] Figure 6A A method for performing the measurements as described herein is shown. Figure 6B A description is provided for use with the optical measurement system described herein to perform... Figure 6A An exemplary phase encoding matrix of the method.

[0026] It should be understood that the proportions and dimensions (relative or absolute) of the various features and elements (as well as their sets and groups), and the boundaries, spacing, and positional relationships therebetween, are provided in the accompanying drawings solely to facilitate understanding of the various embodiments described herein, and are therefore unnecessarily presented or shown to measure and not intended to indicate any preference or requirement for the illustrated embodiments, in order to exclude embodiments in conjunction with them. Detailed Implementation

[0027] Reference will now be made specifically to the representative embodiments shown in the accompanying drawings. It should be understood that the following description is not intended to limit the embodiments to a single preferred embodiment. Rather, it is intended to cover alternative forms, modifications, and equivalents that may be included within the substance and scope of the embodiments defined by the appended claims.

[0028] The following disclosure relates to an optical measurement system that uses multiple emitters to emit light during measurement, and methods for performing measurements using these optical measurement systems. The optical measurement system may include: a light generating component configured to generate light via a light source unit; and a photonic integrated circuit including an emission group having multiple emitters. Each of these emitters is optically coupled to the light generating component to receive light generated from the light generating component and is capable of emitting the light from a surface of the photonic integrated circuit. The optical measurement system is capable of performing measurements wherein the light generating component generates light and each of the multiple emitters simultaneously emits light received from the light generating component.

[0029] Each emitter emits light in a corresponding phase state representing the relative phase of the light. The phase state of each of the plurality of emitters defines the measurement states of the plurality of emitters (and thus the emission group). During measurement, the emission group can change between a plurality of different target measurement states, wherein each target measurement state defines a target phase state of each of the plurality of emitters. Changing between different target measurement states alters the phase state of at least one of the plurality of emitters. Changing between different target measurement states during measurement reduces coherent noise associated with measurements as described herein.

[0030] The optical measurement system described herein can be configured such that a given measurement utilizes only target measurement states having a common phase state distribution. As used herein, the “phase state distribution” of a measurement state refers to the relative number of emitters configured to emit each phase state of a given measurement state. For example, when selecting each phase state of a measurement state from a binary candidate state pair (i.e., each emitter having a first phase state or a second phase state), the phase state distribution refers to the number of emitters having both the first and second phase states. Two measurement states having a common phase state distribution will have the same number of emitters having both the first and second phase states, as described in more detail herein. In some cases, the optical measurement system is configured such that light emitted by an emission group repeatedly cycles between multiple measurement states having a common phase state distribution. In some cases, the optical system can perform multiple measurements, during which a first measurement (or a set of measurements) is performed using a first plurality of measurement states having a first common phase state distribution, and a second measurement (or a set of measurements) is performed using a second plurality of measurement states having a second common phase state distribution different from the first common phase state distribution.

[0031] To set the measurement state of the emitter group, the photonic integrated circuit of the optical measurement system described herein may include a phase shifter array operatively connected to the emitter group. The phase shifter array includes multiple phase shifters, and each of these phase shifters is controllable to change the phase state of a corresponding emitter in the emitter group. Therefore, the phase shifter array can be controlled to set the measurement state of the emitter group by setting the phase state of the individual emitters of the emitter group. The phase shifter array is controlled to change the emitter group between target measurement states having a common phase state distribution, and the phase shifter array can advantageously provide a balanced load to the power supply of the optical measurement system. A driver configured to control the phase shifter array to set these load-balanced measurement states is also described herein.

[0032] The following is for reference Figures 1A to 6B These and other implementation schemes are discussed. However, those skilled in the art will readily understand that the detailed descriptions given herein with respect to the accompanying drawings are for illustrative purposes only and should not be construed as limiting.

[0033] Implementations of the optical measurement system described herein can be incorporated into a housing device. In some cases, the wearable device can operate independently to perform measurements using the optical measurement system, or it can be a multifunctional device capable of performing additional functions (not discussed in detail herein). For example, in some cases, the optical measurement system can be incorporated into a smartphone, tablet computer, laptop or desktop computer, smartwatch or other wearable device, or other electronic device (collectively referred to herein as "electronic device" for ease of discussion).

[0034] The device may include a display (which may be a touchscreen display) that provides graphic output that can be viewed through or on the outer surface of the device. When the display is configured as a touchscreen, it may be able to receive touch input at the outer surface. The device may include a cover (e.g., a cover glass) located above the display, forming at least a portion of the outer surface. The display is capable of providing graphic output and, when configured as a touchscreen, is capable of receiving touch input through the cover. In some embodiments, the display includes one or more sensors (e.g., capacitive touch sensors, ultrasonic sensors, or other touch sensors) positioned above, below, or integrated with the display portion. In various embodiments, the graphic output of the display responds to input provided to the electronic device. Portable electronic devices may include typical additional components of computing devices, including processing units, memory, input devices, output devices, additional sensors, etc.

[0035] Figure 1A and Figure 1B An example of a device 100 that houses an optical measurement system 102 as described herein is shown. Figure 1AA side view of device 100 is shown, which includes, for example, a housing 104 having a top outer surface 106 (housing 104 in...). Figure 1A The image is depicted as a cross-section, showing a side view of the components of an optical measurement system 102 positioned within a housing 104. The top outer surface 106 defines a sampling interface 107 for the optical measurement system 102, through which light emitted by the optical measurement system 102 can exit the device 100 and re-enter to return to the optical measurement system 102. The sampling interface 107 includes at least one window defining one or more emission regions 108 (through which light emitted by the optical measurement system 102 can exit the device 100) and one or more collection regions 110 (through which light entering the device 100 can reach predetermined portions of the optical measurement system 102, such as detectors). Figure 1A and Figure 1B In the variant shown, the device includes multiple emission areas 108 and multiple collection areas 110. Although Figure 1A and Figure 1B An equal number of emitting regions 108 and collecting regions 110 are depicted; however, in other cases, the sampling interface 107 has an unequal number of emitting regions 108 and collecting regions 110. Each emitting region 108 and collecting region 110 is transparent at any one or more wavelengths (collectively, “measurement wavelengths”) used by the optical measurement system 102 to perform the measurements discussed herein. Each emitting region 108 and collecting region 110 may be defined by corresponding windows (transparent at the measurement wavelength) separated from each other by one or more opaque portions of the housing (i.e., absorbing or otherwise blocking light transmission at the measurement wavelength). In other variations, some or all of the emitting regions 108 and / or collecting regions 110 are defined within a common window (e.g., using a mask that is opaque at the measurement wavelength). Additionally or alternatively, the device 100 may include barriers, baffles, or other light-blocking structures (not shown) that may at least partially define some or all of the emitting regions 108 and collecting regions 110. These light-blocking structures block stray light and act as guides to limit the path that light can take between the optical measurement system 102 and the sampling interface 107.

[0036] like Figure 1A and Figure 1BAs shown, the optical measurement system 102 includes a photonic integrated circuit 112. The photonic integrated circuit 112 includes one or more emission groups and is capable of selectively emitting light from each emission group. In cases where the photonic integrated circuit 112 includes multiple emission groups, it is capable of emitting light from each of these emission groups. Light emitted from each emission group of the photonic integrated circuit 112 exits the device 100 via a sampling interface 107 (e.g., via a corresponding emission region 108). In some variations, the optical measurement system 102 optionally includes one or more light modification components (schematically shown as block 114) positioned between the photonic integrated circuit 112 and the sampling interface 107, which modify the light before it reaches the sampling interface 107. For example, the light modification component 114 may include one or more lenses (which alter the divergence and / or direction of light), one or more diffusers, mirrors, etc. Additionally or alternatively, the sampling interface 107 itself may act as a light modification component (e.g., it may have an integrated lens capable of altering the divergence and / or direction of light passing through it). Light emitted from a given emission group interacts with the sampling interface 107 and any intermediate components (such as the light modification component 114) to control the location from which the light exits from the device 100, and thus defines the emission sites of the optical measurement system 102. In cases where the photonic integrated circuit 112 includes multiple emission groups, the optical measurement system 102 may include multiple distinct emission sites from which light may be emitted from the optical measurement system 102 (and therefore from the device 100 incorporating the optical measurement system 102).

[0037] The optical measurement system also includes one or more detector groups 116, each of which includes a corresponding group of detectors. Each detector group 116 is positioned within device 100 to receive light that has entered device 100 through sampling interface 107 (e.g., via a corresponding collection area 110). In some variations, the optical measurement system 102 includes one or more light modification components (schematically shown as block 118) positioned between sampling interface 107 and at least one detector group 116, which modify the light before it reaches the corresponding detector group (or groups). The light modification component 118 may include one or more lenses (which modify the divergence and / or direction of light), one or more diffusers, mirrors, etc. Additionally or alternatively, sampling interface 107 may act as a light modification component (e.g., it may have an integrated lens, etc., capable of modifying the divergence and / or direction of light passing through it), which modifies the light before it reaches detector group 116.

[0038] In some cases, the photonic integrated circuit 112 and one or more detector groups 116 are mounted to a common component. For example, in Figure 1A and Figure 1B In the illustrated variant, the optical measurement system 102 includes an interposer layer 120. In these cases, the photonic integrated circuit 112 and one or more detector groups 116 are all mounted on the interposer layer 120, which then serves as an electrical interface for these components (e.g., routing signals to and / or from these components). In some cases, the interposer layer also acts as a heat sink. In other variants, the photonic integrated circuit 112 is mounted to a component separate from some or all of the detector groups in the detector group 116. In other variants, some or all of the detector groups in the detector group 116 are directly mounted (or otherwise integrated into) a portion of the photonic integrated circuit 112.

[0039] Each detector group 116 can measure light received by the optical measurement system 102 during measurement (e.g., light emitted from the optical measurement system toward the sample and returning to the optical measurement system). The light measured by the detector group during measurement can be analyzed to determine one or more properties of the environment surrounding the optical measurement system 102 (collectively referred to herein as the “sample”) (e.g., the presence, type, and / or one or more characteristics of an object measured by the optical measurement system). Light can be measured by the detector group while the corresponding emission group is emitting light (to determine how the emitted light interacts with the sample), and optionally, light can also be measured when the corresponding emission group is not actively emitting light (to measure background light that may aid in background correction operations).

[0040] Each detector group 116 may be associated with a corresponding emission group, such that each detector group 116 is positioned to measure light emitted by the corresponding emission group and returned to the optical measurement system 102 (e.g., through interaction with a sample outside the optical measurement system). The optical measurement system 102 may be configured such that when the optical system is used to measure aspects of a sample of a predetermined type, light emitted by one emission group will not reach detector groups associated with other emission groups. In this way, each emission group and its corresponding detector group can perform measurements of corresponding portions of the sample without interfering with other measurements being performed simultaneously by another emission group / detector group.

[0041] For example, the optical measurement system 102 may include: a plurality of emission groups, including a first emission group and a second emission group; and a plurality of detector groups, including a first detector group and a second detector group. Components of the optical measurement system 102 may be controlled (e.g., using a controller as described herein) to perform a first measurement using the first emission group and the first detector group, and to perform a second measurement using the second emission group and the second detector group. The first and second measurements may be performed simultaneously, such that the first emission group and the second emission group simultaneously emit light for at least a portion of each of the first and second measurements.

[0042] Figure 2 A schematic diagram of an optical measurement system 200 as described herein is shown. The optical measurement system 200 includes a set of emission groups 202a to 202d, a light generating assembly 204, and a set of detector groups 206a to 206d. The light generating assembly 204 is configured to generate light and deliver it to the set of emission groups 202a to 202d, thereby allowing each emission group 202a to 202d to emit light. Therefore, light can exit the optical measurement system 200 via the set of emission groups 206a to 206d, and the optical measurement system 200 can use some or all of the detector groups 206a to 206d to measure the light returning to the optical measurement system 200. Although the optical measurement system 200 in… Figure 2 The optical measurement system 200 is shown as having four emission groups 202a to 202d and four detector groups 206a to 206d, but it should be understood that the optical measurement system 200 may include any number of emission groups and detector groups. For example, some embodiments of the optical measurement system described herein may include a single emission group and a single detector group. In fact, the principles of a single emission group / detector pair discussed herein for use in optical measurement systems can be extended to any or all of the other emission groups and detector groups in an optical measurement system.

[0043] The light generating assembly 204 may include a light source unit 208 having a set of light sources (not shown), each of which can be selectively operated to emit light at a corresponding set of wavelengths. The set of light sources can be controlled to generate light delivered from the light generating assembly 204 to the set of emission groups 202a to 202d. Each light source can be any component capable of generating light of one or more specific wavelengths, such as a light-emitting diode or a laser. Lasers may include semiconductor lasers, such as laser diodes (e.g., distributed Bragg reflector lasers, distributed feedback lasers, external cavity lasers), quantum cascade lasers, etc. A given light source may be single-frequency (fixed wavelength) or tunable to selectively generate one wavelength from a plurality of wavelengths (i.e., the light source can be controlled to output different wavelengths at different times). The set of light sources may include any suitable combination of light sources and can work together to generate light of any wavelength from a plurality of different wavelengths.

[0044] In some variations, the light source unit 208 includes multiple sets of light sources, each set of light sources being associated with a corresponding emission group among the emission groups 202a to 202d. In these cases, each emission group can receive light generated from different sets of light sources in the light source unit 208. In other variations, multiple emission groups among the emission groups 202a to 202d can receive light from a common set of light sources in the light source unit 208. For example, the light generating assembly 204 may include a switching network 210 configured to selectively deliver light generated by the light source unit 208 to any or all of the emission groups 202a to 202d.

[0045] Specifically, the switching network 210 receives light from the light source unit 208 via one or more inputs, each of which is optically coupled to a corresponding output of the light source unit 208 to receive light therefrom. The switching network 210 may include multiple outputs, each of which is connected to a corresponding emission group among the emission groups 202a to 202d. The switching network 210 may be controllable to receive light received at one of its inputs and simultaneously direct that light to some or all of its outputs. For example, the switching network 210 may be configured, in a first case, to deliver light from the light source unit 208 to a single emission group (e.g., the first emission group 202a), or simultaneously to deliver light to multiple emission groups (e.g., all four emission groups 202a to 202d). In these cases, the light source unit may include relatively fewer light sources, as a single light source can be used to provide light to multiple emission groups.

[0046] Each of the detector groups 206a to 206d includes one or more groups of detector elements. Each detector element is capable of generating a corresponding signal representing the light incident upon it, and these corresponding signals can collectively form a set of output signals for the detector group. Individual detector elements can be independent detectors or single sensing elements of a larger detector array (e.g., photodiodes of a photodiode array). It should be understood that different sensing elements of a single detector array can be associated with different detector groups. For example, a detector array may include a first subset of sensing elements associated with a first detector group and a second subset of sensing elements associated with a second detector group. It should also be understood that detector elements within a given detector group of the detector groups 206a to 206d do not need to be adjacent to each other. Overall, the detector groups 206a to 206d measure light emitted from the optical measurement system 200 via the emission groups 202a to 202d, which facilitates the various measurements described herein.

[0047] As discussed herein, each of the emission groups 202a to 202d is formed as part of the photonic integrated circuit 214. Some or all of the light-generating components of the light-generating assembly 204 (e.g., light source unit 208 and / or switching network 210) may also be integrated into the photonic integrated circuit 214. For example, in some cases, the entire light source of the light source unit 208 is integrated into the photonic integrated circuit 214, such as... Figure 2 As shown. In other cases, some or all of the light sources generate light from outside the photonic integrated circuit 214, and the light from these light sources is coupled into the photonic integrated circuit 214 to reach one or more of the emission groups 202a to 202d. The photonic integrated circuit 214 may utilize waveguides to optically connect components on the photonic integrated circuit 214. For example, in Figure 2 In the illustrated embodiment, each of the emission groups 202a to 202d can be optically coupled to the light generating component 204 via a corresponding waveguide.

[0048] Optical measurement system 202 can be configured such that when the optical system is used to measure aspects of a sample of a predetermined type, light emitted by one of the emission groups 202a to 202d will not reach the detector groups associated with the other emission groups 202a to 202d. For example, in some variations, the first emission group 202a is paired with the first detector group 206a, and the second emission group 202b is paired with the second detector group 206b. In these cases, optical measurement system 202 can be configured such that the first detector group 206a is positioned such that it receives light generated by the first emission group 202a but not light generated by the second emission group 202b during operation of optical measurement system 202. Similarly, the second detector group 206b is positioned such that it receives light generated by the second emission group 202b but not light generated by the first emission group 202a during operation of optical measurement system 202. In these ways, the two emission group-detector pairs can simultaneously perform measurements of different parts of the sample without crosstalk. In addition, in these variations, each emitter-detector pair may be associated with different emitter regions 108 and collection regions 110, as discussed herein, or may be associated with the same emitter regions 108 and collection regions 110.

[0049] Figure 2The document also illustrates a controller 212 that controls the operation of the optical measurement system 200 to perform various measurements as described herein. Specifically, the controller 212 can control the light-generating assembly 204 to generate light and deliver it to one or more of the emission groups 202a to 202d. For example, in the case where the light-generating assembly 204 includes both a light source unit 208 and a switching network 210, the controller 212 can control one or more light sources of the light source unit 208 to generate light of a selected wavelength (or multiple selected wavelengths). The controller 212 can also control the switching network 210 to deliver light received from the light source unit 208 to a selected number of emission groups 202a to 202d. The controller 212 can also control the detector groups 206a to 206d to generate sets of output signals from some or all of the detector groups 206a to 206d, wherein these sets of output signals represent light received by the detector elements of the detector groups 206a to 206d. These sets of output signals can be processed and analyzed to determine one or more properties of the sample. Controller 212 may include any combination of software, hardware and firmware required to perform these functions (including any method steps described below), including, for example, one or more processors and / or application-specific integrated circuits (ASICs).

[0050] As described herein, each emitter group of a photonic integrated circuit can be used to emit light from the photonic integrated circuit, which can also be emitted from an optical measurement system to perform measurements on a sample. When the light source of the light source unit described herein includes a coherent light source (such as a laser), measurements performed using coherent illumination may suffer from coherent noise (also referred to herein as “speckle” noise). Specifically, interference of coherent light as it is scattered through the sample can cause spatial intensity variations in the light received by the detector group, which can reduce the SNR of a given measurement. Therefore, it may be desirable to configure the system to reduce speckle noise (also referred to herein as “despeckle”) for a given measurement performed by an optical measurement system as described herein.

[0051] Therefore, some or all of the emission groups in a given photonic integrated circuit comprise multiple individual emitters. Each emitter is optically coupled to a light-generating component to receive light from it and thereby emits light received from the light-generating component. The light emitted by the multiple emitters of a given emission group collectively forms the light emitted by that emission group. In these cases, each emission group is configured such that each emitter in its corresponding emitter emits light at a different position and / or angle, and the optical measurement system is configured such that the light emitted from each emitter is also introduced into the sample at a different position and / or angle relative to the light emitted by the other emitters in that emission group. If the angle and / or position are sufficiently different between a pair of emitters, the light emitted from that pair of emitters may produce an uncorrelated speckle noise pattern. Capturing the uncorrelated speckle noise pattern between the emitters of the emission group reduces the overall speckle noise associated with a given measurement.

[0052] However, simultaneously emitting light from all transmitters in the emission group does not necessarily improve the speckle noise of a given measurement, because light from each transmitter in the emission group may be coherent with other transmitters. To reduce speckle noise, it is preferable to incoherently sum the relative contributions of each transmitter to the total measurement signal. In one example, light may be emitted sequentially by each transmitter in the emission group, such that only one transmitter emits light at a given time. These individual “sub-measurements” can be incoherently summed to produce a measurement with reduced speckle noise.

[0053] In some cases, design constraints associated with a given optical measurement system may make configuring the system to sequentially deliver light to a single emitter in a group of emitters impractical or otherwise undesirable, especially as the number of emitters associated with the group increases. Alternatively, multiple emitters in the group can emit light simultaneously, but the phase states of these emitters can be changed during the measurement process to alter the relative phase of the light emitted by the multiple emitters. In other words, the measurement states of the group of emitters and its multiple emitters can be changed over time between multiple target measurement states to alter the relative phase of the light emitted by the multiple emitters. Depending on the choice of these target measurement states, changing the measurement states within a given measurement can provide a similar amount of speckle removal as if light were emitted sequentially from each of the multiple emitters.

[0054] For example, Figure 3 A schematic diagram of a portion of the optical measurement system 300 as described herein is shown. As illustrated here, the optical measurement system 300 includes a transmitter group 302 (formed as part of a photonic integrated circuit as described herein), optically coupled to a light generating component 306, such that the transmitter group 302 receives and emits light generated by the light generating component 306. Although the light generating component 306 is... Figure 3The image shown is configured to have a light source unit 312 (which can be as described herein). Figure 2 The light source unit 312 may be configured in any of the ways described for the light source unit 208, but it should be understood that the light generating assembly 306 may also include a switching network (not shown) that can selectively couple the light source unit 312 to the emission group 302. In these cases, the switching network may also optically couple the light source unit 312 to other emission groups (not shown) of the photonic integrated circuit to selectively deliver light to some or all of these emission groups.

[0055] exist Figure 3 In the variant shown, the emitter group 302 includes a plurality of emitters 304a to 304p. Each emitter may be configured as an external coupler (e.g., an edge coupler, a vertical output coupler, etc.) and is configured to emit light from the photonic integrated circuit at a predetermined position and angle relative to the emitter group 302. Although Figure 3 Sixteen emitters 304a to 304p are shown, but it should be understood that each emitter group of the optical measurement system described herein can have any suitable number of emitters as needed, and different emitter groups within the optical measurement system can have different numbers of emitters. Each of the multiple emitters 304a to 304p can emit a corresponding beam, and these beams can collectively form the total beam emitted by emitter group 302. For example, Figure 3 A first transmitter 304a emitting a first beam 340a, a second transmitter 304b emitting a second beam 340b, and a third transmitter 304c emitting a third beam 340c are shown. Although each of the first beam 340a, the second beam 340b, and the third beam 340c is positioned relative to the photonic integrated circuit at different locations and / or angles (which may be sufficiently different from those introduced into the sample as described herein to allow speckle noise decorrelation between these beams), there may be some overlap between these beams after they are emitted from the photonic integrated circuit, such that the individual beams form a larger aggregate beam.

[0056] In some cases, each of the multiple emitters 304a to 304p is optically connected to a different set of light sources to receive light from its corresponding set of light sources. In other cases, the design of the light source unit can be simplified so that some or all of the multiple emitters 304a to 304p receive light from the same set of light sources. For example, in some variations, the optical measurement system 300 includes one or more optical splitters (e.g., which may be formed as part of a photonic integrated circuit) configured to receive light from the output of the light source unit 312 and split the received light among some or all of the emitters 304a to 304p. Figure 3In the illustrated variant, the optical measurement system 300 includes one or more optical splitters (described as a single optical splitter 314 for ease of illustration) that receive light from the output of the light generating assembly 306 (e.g., directly from the light source unit 312, or indirectly from the light source unit 312 via a switching network or another intermediate optical component as described herein) and split the received light among all the emitters 304a to 304p. In these cases, the one or more optical splitters may include star couplers, cascaded optical splitter arrays (e.g., 1×2 optical splitters, etc.), other 1×N or M×N optical splitters, combinations thereof, etc.

[0057] Figure 3 The diagram also shows a phase shifter array 308 comprising multiple phase shifters 310. Each phase shifter 310 in the array can be controllable to change the phase state of a corresponding emitter among the multiple emitters 304a to 304p. Specifically, changing the phase state of a given emitter alters the phase of the light emitted by that emitter. Figure 3 As shown, the optical measurement system 300 may include a driver 318 configured to individually control each of a plurality of phase shifters 310 such that the plurality of phase shifters 310 collectively set the measurement state of the emission group 302 and its plurality of emitters 304a to 304p. Specifically, the driver 318 may control the plurality of phase shifters to change the emission group between a plurality of different target measurement states, as described herein. The driver 318 may be controlled by a controller 316 that provides the target measurement states to the driver 318. The controller 316 may also control the light generating assembly 306 as described herein. Although each of the plurality of emitters 304a to 304p is in Figure 3 The corresponding phase shifter 310 of the phase shifter array 308 is shown in the diagram, but it should be understood that one or more of the multiple transmitters 304a to 304p may not be associated with the corresponding phase shifter 310 of the phase shifter array 308 (e.g., the sixteenth transmitter 304p may not be associated with the phase shifter 310 of the phase shifter array 308). In these cases, the phase shifter array 308 will not be able to adjust the phase state of any such transmitter.

[0058] Individual phase shifters 310 of phase shifter array 308 can be configured in any suitable manner to change the phase state of their respective transmitters, and phase shifter array 308 can include any combination of phase shifter designs as needed. For example, in some variations, phase shifter array 308 may include one or more thermo-optical phase shifters that change the refractive index of a portion of a waveguide (e.g., a waveguide carrying light from light generation component 306 and a given transmitter) by changing the temperature of the waveguide, thereby inducing a phase shift in the light carried by the waveguide. Additionally or alternatively, phase shifter array 308 may include one or more carrier-based phase shifters that change the refractive index of a portion of the waveguide by changing the concentration of charge carriers in the waveguide, thereby inducing a phase shift in the light carried by the waveguide. In some of these cases, a portion of the waveguide forms a portion of a diode (e.g., a PN diode, PIN diode, PIPIN diode, etc.), such that the current through the diode changes the concentration of charge carriers in the waveguide.

[0059] Additionally or alternatively, the phase shifter array 308 may include one or more optomechanical phase shifters that utilize a movable structure, such as a film or suspended waveguide, to change the amount of evanescent coupling with the waveguide. Changing the position of the movable structure alters the effective refractive index experienced by light traveling through the waveguide, thereby inducing a phase transition in the light. An actuator, which may include a microelectromechanical system (“MEMS”), may be used to change the position of the movable structure. In some of these variations, the optomechanical phase shifter may include a MEMS actuator with a bistable structure, such that the movable structure moves between two positions. In these cases, the optomechanical phase shifter effectively has two states: an “on” state, in which a specific phase transition is applied to the light in the waveguide; and an “off” state, in which the phase change is removed. Therefore, a given phase shifter 310 of the phase shifter array 308 may be able to enable the transmitter to change between three or more different phase states, or may be limited to two different phase states, depending on its design.

[0060] When the optical measurement system 300 is used to perform measurements, the controller 316 can be configured to selectively change the measurement state of the emission group 302 during a given measurement. For example, the emission group (e.g., by controlling the light generating assembly 306 with the controller 316) can be controlled to simultaneously generate light from each of a plurality of emitters 304a to 304p. While the plurality of emitters 304a to 304p emit light simultaneously, the measurement state of the emission group can be changed between multiple target measurement states. Detector groups (such as...) Figure 2One of the detector groups 206a to 206 can measure the returned light (i.e., the light entering the optical measurement system) received when the light is emitted from the emission group. Due to the change in the measurement state during the measurement process, the output signal set generated by the detector during this measurement period can average some of the speckle noise and increase the SNR of the output signal set.

[0061] For example, the driver 318 can use a phase encoding matrix (which can be received from the controller 316) to set the measurement state of the transmitter group 302 at each time point by setting the phase states of multiple transmitters 304a to 304p. Figure 4A and Figure 4B Examples of phase encoding matrices 400 and 402 are shown, which can be used by the optical measurement system described herein to set the relative phase of light emitted by multiple emitters in an emission group. Figure 4A Taking phase encoding matrix 400 as an example, the matrix elements of phase encoding matrix 400 represent the phase state applied to a given transmitter at a given time. Figure 4A In the phase encoding matrix 400, each matrix element has a value of 0 or 1, where 0 represents a first phase state (e.g., where one or more phase shifters associated with the transmitter do not actively change the phase of the light emitted by the transmitter), and 1 represents a second phase state (e.g., where one or more phase shifters associated with the transmitter actively apply a predetermined phase shift to the light emitted by the transmitter). It should be understood that in other cases, the phase encoding matrix may include three or more phase states, in which case each phase state represents a different amount of phase shift provided to the light emitted from a given transmitter. This allows the phase shifter array described herein to provide greater granularity for phase transitions generated for different measurement states.

[0062] Each row of the phase encoding matrix 400 represents the phase state of a given transmitter in the transmission group during different target measurement states. Figure 4A The phase coding matrix 400 has sixteen rows, such that each row of the phase coding matrix 400 can correspond to Figure 3 The phase encoding matrix 400 comprises multiple transmitters 304a to 304p, each representing a different target measurement state. The columns of the phase encoding matrix 400 represent different target measurement states. Therefore, the phase encoding matrix defines multiple measurement states. For example, the first column defines a first measurement state, where the first transmitter 304a (as determined by the first row of the phase encoding matrix 400) is set to phase state 1, the second transmitter 304b (as determined by the second row of the phase encoding matrix 400) is set to phase state 0, and so on. When the measurement state changes to the measurement state in column 2, the first transmitter 304a continues to have phase state 1, the second transmitter switches from phase state 0 to phase state 1, and so on. Therefore, each element within the phase encoding matrix 400 represents the phase of a specific transmitter during a particular measurement state.

[0063] During a given measurement, the phase encoding matrix 400 can be used to change the state of multiple transmitters between different measurement states. Figure 4A The exemplary phase encoding matrix 400 depicts fifteen different measurement states, but it should be understood that the phase encoding matrix 400 may have a different number of measurement states (e.g., Figure 4B The phase encoding matrix 402 has sixteen different measurement states. Multiple transmitters 304a to 304p can emit light in each of these fifteen measurement states during a single measurement, which can result in the incoherent addition of the contributions from the different transmitters 304a to 304p (and thus provide speckle removal of the output signal of the measurement as described herein).

[0064] In some variations, multiple transmitters 304a to 304p can repeatedly cycle through multiple target measurement states multiple times during a given measurement. In these cases, driver 318 can control phase shifter array 308 to sequentially change the emission group between each of the multiple target measurement states defined by phase encoding matrix 400, such that the emission group emits light in each target measurement state (e.g., emitting in a first target measurement state during a first time period, emitting in a second measurement state during a second time period after the first time period, and so on). Once light has been emitted by the emission group in each measurement state defined by phase encoding matrix 400, driver 318 can perform a second iteration, wherein driver 318 controls phase shifter array 308 to again sequentially change the emission group between each of the multiple target measurement states defined by phase encoding matrix 400. This can be repeated continuously throughout the duration of the measurement. In some variations, different iterations can change the order in which the emission group changes between the multiple target measurement states defined by phase encoding matrix 400. Therefore, in some variations, during a given measurement period, the emission group (and thus multiple emitters) emits light only in the measurement state with a common phase distribution.

[0065] Different choices of values ​​within the phase encoding matrix can provide different levels of speckle reduction. Therefore, some phase encoding matrices can better approximate speckle noise reduction achievable by sequentially emitting light using multiple emitters. For example, in the case where a phase shifter array provides a binary selection of phase states for each emitter in a transmission group, phase encoding matrix 400 can be configured as a Hadamard matrix, where the phase encoding matrix is ​​a square matrix whose rows are mutually orthogonal.

[0066] In some cases, the optical measurement system described herein can be configured to change the measurement state of the transmitter group between multiple target measurement states having a common phase state distribution during measurement. This provides load balancing while simultaneously reducing speckle noise. Additionally, the multiple different measurement states are configured such that each measurement state has a common phase state distribution. When the phase state distribution is the same across multiple measurement states, the phase shifter array can use the same amount of power across these measurement states (but it should be understood that in practice, small temporary fluctuations may exist when controlling individual phase shifters to change the phase state of a given transmitter). Therefore, the phase shifter array can provide a balanced load to the power supply powering the phase shifter array. Since the power supply does not need to account for power fluctuations that will occur when switching between measurement states with different phase state distributions, the optical measurement system can switch rapidly between different target measurement states. This relaxes the design requirements of the optical system (such as by allowing the power supply to be positioned further away from the phase shifter array) and reduces the total power consumed by the phase shifter array during operation.

[0067] Figure 4A and Figure 4B The phase encoding matrices 400 and 402 are both load-balanced matrices, where each measurement state has a common phase distribution. For example, Figure 4A A 16×15 phase coding matrix 400 is depicted for a transmitter group having 16 transmitters (represented by 16 rows of phase coding matrix 400). As discussed herein, each of the fifteen measurement states (represented by fifteen columns of phase coding matrix 400) has the same phase state distribution (i.e., each measurement state has eight transmitters set to phase 0 and eight transmitters set to phase 1). Figure 4A The 16×15 phase encoding matrix 400 is a 16×16 Hadamard matrix in which one column has been removed, specifically the column in which each row has the same phase state to generate the 16×15 matrix.

[0068] Similarly, Figure 4B The phase encoding matrix 402 is a 16×16 matrix (represented by the 16 rows of the phase encoding matrix 402) for a transmitter group with 16 transmitters. In this variant, each of the 16 measurement states (represented by the 16 columns of the phase encoding matrix 402) has the same phase state distribution (i.e., each measurement state has six transmitters set to phase 1 and ten transmitters set to phase 0). In some of these cases, the phase encoding matrix 402 can be derived from the tensor product of a cyclic 4×4 Hadamard matrix and itself. Although Figure 4A and Figure 4BBoth implementations of the phase encoding matrices 400 and 402 utilize a binary selection of the phase state within each measurement state; however, it should be understood that the phase encoding matrix can still be load-balanced with three or more phase states in each measurement state. In these cases, different measurement states will still have the same phase state distribution (e.g., each measurement state will have the same number of transmitters set to the first phase state, the same number of transmitters set to the second phase state, the same number of transmitters set to the third phase state, and so on).

[0069] Using a load-balanced phase encoding matrix with binary selection of phase states allows for the control of phase shifter arrays as described herein using streamlined, power-efficient drivers. For example, Figure 5A A variation of a driver 500, which can be used to control a phase shifter array as described herein, is shown. As shown, the driver 500 controls the operation of multiple phase shifters 502a to 502d of the phase shifter array. Although Figure 5A Four phase shifters 502a to 502d are shown, but it should be understood that the driver 500 can be used to control any number of phase shifters (e.g., Figure 3 The sixteen phase shifters 310 shown.

[0070] The driver 500 includes a plurality of switches 504a to 504d defining a plurality of switch-shifter pairs. Each switch-shifter pair is formed by a phase shifter among a plurality of phase shifters 502a to 502d and a switch among a plurality of switches 504a to 504d connected in parallel with the phase shifter. For example, Figure 5A Four switch-shifter pairs are shown (i.e., a first phase shifter 502a and a first switch 504a are connected in parallel to form a first switch-shifter pair, a second phase shifter 502b and a second switch 504b are connected in parallel to form a second switch-shifter pair, a third phase shifter 502c and a third switch 504c are connected in parallel to form a third switch-shifter pair, and a fourth phase shifter 502d and a fourth switch 504d are connected in parallel to form a fourth switch-shifter pair). Multiple switch-shifter pairs are connected in series to a power supply 506 of the optical measurement system.

[0071] Each switch-shifter pair is configured to set the phase state of the corresponding transmitter in the emission group, as described herein. Specifically, the switch of a given switch-shifter pair (e.g., the first switch 504a) can be turned off so that current supplied by power supply 506 passes through the phase shifter of the switch-shifter pair (e.g., the first phase shifter 502a). This current drives the phase shifter to change the phase of the light emitted by its corresponding transmitter, thereby setting the first phase state of the transmitter. Conversely, the switch of the switch-shifter pair can be turned on so that current bypasses the phase shifter of the switch-shifter pair. In these cases, the phase shifter is effectively turned off and no phase transition is applied to the light emitted by the corresponding transmitter, thereby setting the second phase state of the transmitter.

[0072] In general, the driver 518 can selectively control multiple switches to set a desired measurement state. When the driver 518 is used to set multiple measurement states with a common phase distribution, the same number of switches will be turned on (and thus the same number of switches will be turned off) for each of these measurement states. Therefore, even when the measurement state changes, a constant number of phase shifters will draw current from the power supply 506. Assuming that each phase shifter draws the same amount of current, the power supply 506 will experience the same load as when the driver 518 switches between measurement states.

[0073] Figure 5B Another variation of the driver 540, which can be used to control a phase shifter array as described herein, is shown. The driver 540 controls the operation of multiple phase shifters 502a to 502d of the phase shifter array. Figure 5A The same as the 500 drive. Figure 5A Four phase shifters 502a to 502d are shown, but it should be understood that the driver 540 can be used to control any number of phase shifters as described herein.

[0074] The driver 540 includes a current source array 544, which comprises a plurality of controllable current sources 544a to 544d. For each of the plurality of phase shifters 502a to 502d in the phase shifter array, the driver 540 includes a controllable current source connected in series with the phase shifter. For example... Figure 5B The illustrated current source array 544 includes a first controllable current source 544a connected in series with a first phase shifter 502a, a second controllable current source 544b connected in series with a second phase shifter 502b, a third controllable current source 544c connected in series with a third phase shifter 502c, and a fourth controllable current source 544d connected in series with a fourth phase shifter 502d. The controllable current sources 544a to 544d of the current source array 544 are connected in parallel to the power supply 506 of the optical measurement system.

[0075] Each controllable current source can be switched on or off to selectively activate its corresponding phase shifter. For example, the first controllable current source 544a can be switched on, causing current to be driven through the first phase shifter 502a. This current drives the first phase shifter 502a to change the phase of the light emitted by its corresponding emitter, thereby setting a first phase state of the emitter. Conversely, the first controllable current source 544a can be switched off, causing current not to be driven to the first phase shifter 502a. In these cases, the phase shifter 502a does not impart a phase change to the light emitted by the corresponding emitter, thereby setting a second phase state of the corresponding emitter.

[0076] The driver 540 may include a state decoder 546 that selectively controls controllable current sources 544a to 554d of the current source array 544 to set the desired measurement state of the emitter group. When the driver 540 is used to set multiple measurement states having a common phase state distribution, the same number of controllable current sources are turned on (and thus the same number of controllable current sources are turned off) for each of these measurement states. Therefore, even when the measurement state changes, a constant number of phase shifters will draw current from the power supply 506. Assuming that each phase shifter draws the same amount of current, the power supply 506 will experience the same load as when the driver 540 switches between measurement states.

[0077] In some cases of the optical measurement systems described herein, it may be desirable to change the phase distribution at one or more points within a given measurement. In these cases, the optical measurement system can divide the measurement into multiple measurement stages. Each of the multiple measurement stages is associated with a corresponding phase distribution, and during each measurement stage, the optical measurement system switches between measurement states having the corresponding phase distribution. In other words, the measurement states within each measurement stage have a common phase distribution, and different measurement stages may have different common phase distributions. The optical measurement system can execute one or more measurement sequences as part of a measurement sequence, wherein the measurement sequence includes each measurement stage within the measurement stages. By grouping the measurement states in this way, the overall measurement can experience improved noise reduction and / or reduced power consumption, while reducing the frequency of load changes caused by altering the phase distribution between successive measurement states.

[0078] For example, Figure 6AA method 600 for performing measurements using multiple measurement stages is illustrated, each of which has a different common phase distribution. Specifically, an optical measurement system can perform a measurement sequence, wherein a first portion of the measurement is performed during a first measurement stage, and a second portion of the measurement is performed during a second measurement stage. Performing the measurement during the first measurement stage includes step 602, emitting light in a first plurality of target measurement states having a first common phase distribution. In other words, during the first measurement stage, the emission group of the optical system will emit only light having the first common phase distribution.

[0079] use Figure 3 As an example, the optical measurement system 300 can control the emission group 302 (e.g., by controlling the light generating assembly 306 with a controller 316) during a first measurement phase to simultaneously generate light from each of a plurality of emitters 304a to 304p. While the plurality of emitters 304a to 304p emit light simultaneously, the measurement state of the emission group can be changed between first plurality of target measurement states. Detector groups (such as...) Figure 2 The detector group (one of the detector groups 206a to 206) can measure the returned light (i.e., the light entering the optical measurement system) received when the light is emitted by the emission group. During the first measurement phase, due to the change in the measurement state during the measurement process, the output signal set generated by the detector during this measurement period can average some of the speckle noise in the speckle noise and increase the SNR of the output signal set.

[0080] In some variations, multiple transmitters 304a to 304p may repeatedly cycle through a first plurality of target measurement states multiple times during the first measurement phase. Specifically, in step 604, the method may repeat step 602 once or multiple times. In these cases, driver 318 may perform a first iteration, wherein driver 318 controls phase shifter array 308 to sequentially change the emission group between each target measurement state of the first plurality of target measurement states, such that the emission group emits light in each target measurement state (e.g., emitting in a first target measurement state during a first time period, emitting in a second measurement state during a second time period after the first time period, and so on). Driver 318 may then perform a second iteration, wherein driver 318 controls phase shifter array 308 to again sequentially change the emission group between each target measurement state of the first plurality of target measurement states. This may be repeated continuously multiple times (e.g., repeating iterations a predetermined number of times or continuously repeating within a first time period corresponding to the first measurement phase). In some variations, different iterations within the first measurement phase may change the order in which the emission group changes between the first plurality of target measurement states.

[0081] After completing the first measurement phase, the optical measurement system can perform a second portion of the measurement during the second measurement phase. Specifically, performing the measurement during the second measurement phase includes, in step 606, emitting light in a second plurality of target measurement states having a second common phase distribution (different from the first common phase distribution). In other words, during the second measurement phase, the emission group of the optical system will emit only light having the second common phase distribution. Since each measurement phase utilizes a single corresponding phase distribution, each of these portions of the measurement is load-balanced, such that only load changes occur during the transition between measurement phases.

[0082] During the second measurement phase, the emission group 302 (e.g., by controlling the light generation assembly 306 with controller 316) can be controlled to simultaneously generate light from each of the plurality of transmitters 304a to 304p. While the plurality of transmitters 304a to 304p are simultaneously emitting light, the measurement state of the emission group can be changed between a second plurality of target measurement states. A detector group can measure the returned light received while the emission group is emitting light. During the second measurement phase, due to the changes in the measurement state during the measurement process, the output signal set generated by the detectors during this measurement phase can average some of the speckle noise and increase the SNR of the output signal set. Therefore, the different measurement phases collectively contribute to reducing speckle noise in the overall measurement.

[0083] In some variations, multiple transmitters 304a to 304p may repeatedly cycle through a second plurality of target measurement states multiple times during the second measurement phase. Specifically, in step 608, the method may repeat step 606 once or multiple times. In these cases, driver 318 may perform a first iteration, wherein driver 318 controls phase shifter array 308 to sequentially change the emission group between each target measurement state of the second plurality of target measurement states, such that the emission group emits light in each target measurement state (e.g., emitting in a first target measurement state of the second plurality of target measurement states during a first time period, emitting in a second measurement state of the second plurality of target measurement states during a second time period after the first time period, and so on). Driver 318 may then perform a second iteration, wherein driver 318 controls phase shifter array 308 to again sequentially change the emission group between each target measurement state of the second plurality of target measurement points. This may be repeated continuously multiple times (e.g., repeating iterations a predetermined number of times or continuously repeating within a second time period corresponding to the second measurement phase). In some variations, different iterations within the second measurement phase may change the order in which the emission group changes between the second plurality of target measurement states. Although Figure 6AThe method is shown as including two different measurement stages associated with two different phase distributions, but it should be understood that the principle of method 600 can be extended to include additional measurement stages associated with additional different phase distributions.

[0084] In some cases, the method can cycle through the various measurement stages. For example, in step 610, method 600 can repeat the sequence of the first and second measurement stages. In this way, method 600 can alternate between different phase distributions as needed during the measurement. When the measurement is divided into three or more measurement stages, the optical system can optionally change the order in which each measurement stage is performed between different iterations of the measurement stage sequence.

[0085] The driver 318 can use one or more phase encoding matrices (which can be received from the controller 316) to set the measurement state of the transmitter group 302 at each time point within the measurement. For example, Figure 6B An example of a phase encoding matrix 620 is shown that can be used to control a group of transmitters having 32 transmitters (represented by the rows of a phase encoding matrix 620). Specifically, the phase encoding matrix 620 is a 32×32 matrix comprising a first plurality of target measurement states 622 (represented by the first 16 columns of the phase encoding matrix 620) and a second plurality of target measurement states 624 (represented by the last 16 columns of the phase encoding matrix 620). The first plurality of target measurement states 622 have a distributed first common phase state distribution (i.e., each measurement state has twelve transmitters set to phase 1 and twenty transmitters set to phase 0), and the second plurality of target measurement states 624 have a distributed second common phase state distribution (i.e., each measurement state has 16 transmitters set to phase 1 and 16 transmitters set to phase 0). In some of these cases, the phase encoding matrix 620 may be derived from a cyclic 2×2 Hadamard matrix. Figure 4B The Kronecker tensor product of the phase encoding matrix 402 is derived.

[0086] exist Figure 6A In the example of method 600, the driver 318 may utilize a first plurality of target measurement states 622 during a first measurement phase and a second plurality of target measurement states 624 during a second measurement phase. It should be understood that the different plurality of target measurement sites may be divided into different matrices for use by the driver 318 during the respective measurement phases. Assuming that the measurement uses equal durations between the first and second measurement phases, the average number of phase shifters switched on at one time is fourteen, which is smaller than a Hadamard sequence of a similarly sized matrix. Therefore, Figure 6B The phase coding matrix 620 provides noise reduction while consuming less total power compared to other methods.

[0087] For illustrative purposes, the foregoing description uses specific names to provide a thorough understanding of the described embodiments. However, it will be apparent to those skilled in the art that specific details are not required to practice the described embodiments. Therefore, the foregoing description of specific embodiments described herein is presented for illustrative and descriptive purposes. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to those skilled in the art that many modifications and variations are possible in light of the teachings above.

Claims

1. An optical measurement system, comprising: A light generating component, the light generating component including a light source unit configured to generate light; A photonic integrated circuit, the photonic integrated circuit including an emission group, the emission group including a plurality of emitters, the plurality of emitters being optically coupled to the light generating component to receive light generated by the light generating component; Detector group; as well as A controller configured to perform measurements using the light-generating component, the emission group, and the detector group, wherein the measurements include: The light source unit is used to generate light; The generated light is emitted simultaneously from each of the plurality of emitters, such that the plurality of emitters emit light in a corresponding set of phase states defined by the measurement state; During the simultaneous emission of the generated light, the measurement state is changed between multiple target measurement states having a common phase distribution; The detector array is used to measure the returned light received during the simultaneous emission of the generated illuminated light, wherein: During the measurement, the plurality of emitters emit light only in the measurement state having the common phase distribution.

2. The optical measurement system according to claim 1, wherein: The launch group is the first launch group; The photonic integrated circuit includes a plurality of emission groups, the plurality of emission groups including the first emission group, such that each of the plurality of emission groups is optically coupled to the light generating component to receive light generated by the light generating component; The detector group is the first detector group; and The optical measurement system includes multiple detector groups, including the first detector group.

3. The optical measurement system according to claim 2, wherein: The measurement is the first measurement; The plurality of launch groups includes a second launch group; The plurality of detector groups includes a second detector group; and The controller is configured to perform a second measurement using the light generating component, the second emission group, and the second detector group.

4. The optical measurement system according to claim 3, wherein: The controller is configured to perform the first measurement simultaneously with the second measurement.

5. The optical measurement system according to claim 4, wherein: The photonic integrated circuit includes a phase shifter array, wherein the phase shifter array has multiple phase shifters; Each of the plurality of phase shifters is controllable to change the phase state of light emitted by a corresponding emitter among the plurality of emitters; and The controller is configured to control the phase shifter array during the measurement to adjust the relative phase states of the plurality of transmitters, such that the plurality of transmitters emit light with the corresponding set of phase states for each of the plurality of target measurement states.

6. The optical measurement system according to claim 5, comprising: A driver configured to control the phase state of each of the plurality of phase shifters.

7. The optical measurement system according to claim 6, wherein: The driver includes multiple switch-shifter pairs connected in series with a power supply. and Each of the plurality of switch-shifter pairs includes: The corresponding phase shifter among the plurality of phase shifters; as well as A switch, wherein the switch is connected in parallel with the corresponding phase shifter among the plurality of phase shifters.

8. The optical measurement system according to claim 6, wherein: The driver includes multiple controllable current sources, which are connected in parallel to a power supply; and Each of the controllable current sources is connected in series to a corresponding phase shifter among the plurality of phase shifters.

9. The optical measurement system according to claim 1, wherein: The light generating component includes a switching network that optically couples the light source unit to the plurality of emitters.

10. The optical measurement system according to claim 1, further comprising: Intermediate layer, wherein: The photonic integrated circuit and the plurality of detector groups are mounted on the interposer layer.

11. The optical measurement system according to claim 1, wherein: Each phase from the target measurement states is selected from a plurality of binary pairs of candidate phase states.

12. An optical measurement system, comprising: A light generating component, the light generating component including a light source unit configured to generate light; A photonic integrated circuit, comprising an emitter array and a phase shifter array; as well as Controller, wherein: The launch group includes multiple transmitters; Each of the plurality of transmitters is optically coupled to the light generating component to receive light generated by the light generating component and to emit a corresponding beam of light; The phase shifter array includes multiple phase shifters; Each of the plurality of phase shifters is controllable to set the phase state of the beam emitted by a corresponding emitter among the plurality of emitters; and The controller is configured to: Controlling the light-generating component to generate light, such that the plurality of emitters simultaneously emit light from the photonic integrated circuit; and When the multiple transmitters simultaneously emit light, the phase shifter array is controlled to repeatedly cycle the measurement states of the multiple transmitters between multiple target measurement states; wherein: Each of the multiple target measurement states has a common phase distribution.

13. The optical measurement system according to claim 12, comprising: A detector array, wherein the controller is configured to use the detector array to measure the returned light received when the plurality of transmitters simultaneously emit light.

14. The optical measurement system according to claim 13, further comprising: Intermediate layer, wherein: The photonic integrated circuit and the plurality of detector groups are mounted on the interposer layer.

15. The optical measurement system according to claim 12, comprising: A driver configured to control the phase state of each of the plurality of phase shifters.

16. The optical measurement system according to claim 15, wherein: The driver controls the phase state of each of the plurality of phase shifters based on a phase encoding matrix.

17. The optical measurement system according to claim 15, wherein: The driver includes multiple switch-shifter pairs connected in series with a power supply. and Each of the plurality of switch-shifter pairs includes: The corresponding phase shifter among the plurality of phase shifters; as well as A switch, wherein the switch is connected in parallel with the corresponding phase shifter among the plurality of phase shifters.

18. The optical measurement system according to claim 15, wherein: The driver includes multiple controllable current sources, which are connected in parallel to a power supply; and Each of the controllable current sources is connected in series to a corresponding phase shifter among the plurality of phase shifters.

19. The optical measurement system according to claim 12, wherein: The light generating component includes a switching network that optically couples the light source unit to the plurality of emitters.

20. The optical measurement system according to claim 12, wherein: Each phase from the target measurement states is selected from a plurality of binary pairs of candidate phase states.

21. The optical measurement system according to claim 12, wherein: The plurality of target measurement states are the first plurality of target measurement states; The common phase distribution is the first common phase distribution; The controller is configured to control the phase shifter array to repeatedly cycle between a plurality of target measurement states when the plurality of transmitters simultaneously emit light; and The second plurality of target measurement states have a second common phase distribution that is different from the first common phase distribution.

22. A method for performing a measurement using an optical measurement system, the method comprising: Light is emitted simultaneously from multiple emitters in the photonic integrated circuit's emission array; as well as Execute a measurement sequence, the measurement sequence including a first measurement phase and a second measurement phase, wherein: Performing the first measurement phase includes: While the plurality of transmitters simultaneously emit light, a phase shifter array is controlled to perform at least one first iteration, in which the measurement states of the plurality of transmitters change between a first plurality of target measurement states having a first common phase state distribution; and A detector array is used to measure the returned light received during at least one first iteration; and Performing the second measurement phase includes: While the plurality of transmitters simultaneously emit light, the phase shifter array is controlled to perform at least one second iteration, in which the measurement states of the plurality of transmitters change between a second plurality of target measurement states having a second common phase distribution different from the first common phase distribution; and The detector array is used to measure the returned light received during the at least one second iteration.

23. The method according to claim 22, wherein: Performing the first measurement phase includes performing multiple first iterations.

24. The method of claim 22, wherein: Performing the second measurement phase includes performing multiple second iterations.

25. The method of claim 22, comprising: Repeat the measurement sequence.

26. The method of claim 25, wherein: Repeating the measurement sequence includes changing the order of the first measurement phase and the second measurement phase.

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