Optical scanner

Abstract

The optical phased array (3) of the present application is configured to control the phases of a plurality of branched lights, which are branched from the light supplied from the light source (2) respectively, independently by using scanning phase amounts, and radiate from an antenna array having a plurality of antenna elements, to achieve scanning of the light beam. The monitoring light receiving section (6) is configured to receive the light radiated from the optical phased array. The signal processing section (7) is configured to detect the characteristics of the light beam based on the detection results in the monitoring light receiving section, and generate a phase adjustment amount for correcting the scanning phase amounts so that the detected value of the characteristics coincides with a design value prepared in advance.

Description

Technical Field

[0001] This disclosure relates to optical scanners using optical phased arrays. Background Technology

[0002] It is known that optical phased arrays (hereinafter, OPAs) are used for beam forming and beam steering. OPA is an abbreviation for Optical Phased Array. In an OPA, an antenna array with multiple antenna elements that emit light is used, and the phase shift applied to each antenna element is controlled individually.

[0003] The phase shift applied to each antenna element for beam steering is theoretically uniquely determined based on the antenna array configuration and the wavelength of the light used. However, if the characteristics of the waveguide from the light source to each antenna element change due to temperature variations, errors will occur in the phase shift applied to each antenna element, resulting in unsatisfactory performance in terms of beam profile and exit angle.

[0004] Patent Document 1 below proposes a technique for setting up a phase monitor to monitor the phase of light supplied to each antenna element and for feedback control of the phase of light passing through waveguides connected to each antenna element so that the monitored value is consistent with the target value.

[0005] Patent Document 1: U.S. Patent Application Publication No. 2020 / 0158839

[0006] However, the inventors' detailed research revealed a problem that the prior art could not address the errors caused by the deformation of the substrate, which affected the three-dimensional configuration of the antenna elements.

[0007] That is, the OPA is formed on a substrate called a PIC. PIC is an abbreviation for Photonic Integrated Circuit. When applying the OPA to automotive LiDAR, it is assumed that deformation (e.g., substrate warping) occurs on the PIC substrate due to ambient temperature and heat from other mounting components. LiDAR is an abbreviation for Light Detection and Range. If the substrate deforms, the configuration of the antenna elements changes three-dimensionally, resulting in disruption of the beam profile and shift in the beam exit angle. However, since existing technologies assume a constant three-dimensional configuration of the antenna elements, they cannot address errors caused by substrate deformation affecting the three-dimensional configuration of the antenna elements. Summary of the Invention

[0008] One aspect of this disclosure preferably provides a technique for correcting errors based on variations in the configuration of antenna elements in an optical scanner using an optical phased array.

[0009] One aspect of this disclosure is an optical scanner, comprising a light source, an optical phased array, a light-receiving unit for monitoring, and a signal processing unit. The optical phased array is configured to scan the light beam by independently controlling the phase of multiple branched beams derived from light supplied from the light source using a scanning phase quantity, and radiating them from an antenna array having multiple antenna elements. The light-receiving unit for monitoring is configured to receive light emitted from the optical phased array. The signal processing unit is configured to detect the characteristics of the light beam based on the detection results in the light-receiving unit for monitoring, and generate a phase adjustment amount for correcting the scanning phase quantity so that the detected characteristic value matches a pre-prepared design value.

[0010] Based on this structure, by directly detecting the light beam emitted from the optical phased array into space, the phase of the light propagating in space is directly fed back to the generation of the phase adjustment amount. Therefore, it is possible to compensate for errors, including not only those caused by factors within the circuitry constituting the optical phased array, but also those caused by factors outside the circuitry, such as deformation of the substrate on which the optical phased array is mounted. As a result, it is possible to achieve high-precision optimization of the beam profile and beam scanning. Attached Figure Description

[0011] Figure 1 This is a block diagram showing the structure of the optical scanner according to the first embodiment.

[0012] Figure 2 This is an explanatory diagram illustrating the principle of optical phased arrays.

[0013] Figure 3 It is a diagram representing the illumination pattern of an optical phased array.

[0014] Figure 4 This is an explanatory diagram showing the effect of substrate deformation on the beam profile.

[0015] Figure 5 This is an explanatory diagram showing the relationship between the deformation mode of the substrate and the beam profile.

[0016] Figure 6 This is a flowchart of the typical process in the first embodiment.

[0017] Figure 7 This is a flowchart of the correction process in the first embodiment.

[0018] Figure 8 This is a block diagram showing the structure of the optical scanner according to the second embodiment.

[0019] Figure 9 This is a flowchart of the typical process in the second embodiment.

[0020] Figure 10 This is a flowchart of the correction process in the second embodiment.

[0021] Figure 11 This is an explanatory diagram showing other configuration methods of the light-receiving unit for monitoring.

[0022] Figure 12 This is an explanatory diagram showing an example of the configuration of a monitoring light-receiving unit receiving light through a reflector.

[0023] Figure 13 This is an explanatory diagram showing an example of the configuration of a monitoring light-receiving unit receiving light through a reflector. Detailed Implementation

[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0025] [1. First Implementation Method]

[0026] [1-1. Structure]

[0027] Figure 1 The optical scanner 1 shown includes a light source 2, an optical phased array (i.e., OPA) 3, a detector 4, a phase controller 5, a light receiving unit for monitoring 6, and a signal processing unit 7.

[0028] The optical scanner 1 is housed in the housing 10, and light is irradiated through an opening 11 formed in the front wall of the housing 10. The opening 11 has an angular range (i.e., scanning range) or FOV that does not obstruct scanning by the light beam irradiated from the OPA3. FOV is an abbreviation for Field of View.

[0029] Light source 2 is a device that generates laser light. Here, a continuous wave with a wavelength of 1.5μm or 1.3μm frequency band is used after FM modulation.

[0030] OPA3 is a device that uses the diffraction and interference of light to control the profile shape (i.e., beam profile) and direction of travel of a light beam. OPA3 includes a splitter 31, a phase shifter 32, and an antenna array 33. OPA3 and light source 2 are mounted together on a single PIC substrate.

[0031] The splitter 31 distributes the incident light from the light source 2 to a waveguide array consisting of multiple waveguides. Additionally, the splitter 31 generates a mixed light that combines the incident light from the waveguide array. This mixed light, along with the incident light from the light source 2, is then incident onto the detector 4.

[0032] Phase shifter 32 is disposed in each of the multiple waveguides constituting the waveguide array. By changing the refractive index of the waveguide according to the instruction from phase controller 5 using electro-optic effect, thermo-optic effect, etc., the phase of light passing through each waveguide changes independently.

[0033] Antenna array 33 has K antenna elements (hereinafter, elements) arranged at certain intervals (e.g., K = hundreds to thousands). Individual elements can also be used at the ends of the waveguide array opposite to the connection end of splitter 31.

[0034] The antenna array 33 illuminates the FOV with light supplied from the waveguide array and receives light from the FOV, supplying it to the waveguide array. Alternatively, the antenna array 33 can be configured to illuminate and receive light via a diffraction grating that diffracts and interferes with the light.

[0035] like Figure 2 As shown, OPA3 uses equation (1) to represent the electric field Ek in the θ direction caused by the radiation from the element determined by the identifier k. Here, E0 is the electric field amplitude, EF(θ) is the element coefficient representing the directivity (i.e., the illumination pattern) of the individual element, λ is the wavelength, θ is the direction of travel / arrival of the electromagnetic wave surface, dk is the distance from the reference element determined by k, and φk is the phase given to the element determined by k by the phase shifter 32. Furthermore, the reference element is located at one end of the antenna array 33 (e.g., at...). Figure 2 The element at the left end (with the middle element as the reference element) is represented by k = 0. From thereafter, the value of k increases sequentially, starting with the element closest to the reference element.

[0036] [Number 1]

[0037]

[0038] The combined electric field Esum(θ) formed by the antenna array 33 with K elements is represented by equation (2). Here, AF(θ, λ) is the array coefficient representing the directivity of the antenna array 33 as a whole, and is represented by equation (3).

[0039] [Number 2]

[0040] E sum (θ)=E0*AF(θ,λ) (2)

[0041]

[0042] Equation (4) is the phase condition extracted from equation (3), and the main lobe is formed in the direction θ0 that satisfies the phase condition. In other words, by making the phase φk an appropriate value, the direction θ0 that forms the main lobe can be arbitrarily set. Where m is set to an integer other than 0, under the condition that equation (5) is satisfied, a strong peak is also formed in the θgm direction, that is, the grating lobe.

[0043] [Number 3]

[0044]

[0045]

[0046] Therefore, in OPA3, we obtain the following: Figure 3 The illumination pattern is shown. Generally, the field of view (FOV) is set within the range centered on the direction θ0 that forms the main lobe, excluding the direction θgm that forms the grating lobe with m = ±1. However, there are cases where the FOV is expanded by utilizing the grating lobe, and it is not limited to the above range.

[0047] Detector 4 is constructed using light-receiving elements such as photodiodes. It converts the light generated by being received and mixed by OPA3 into an electrical signal and supplies it as a light-receiving signal to signal processing unit 7. The light-receiving signal becomes a beat signal with the frequency component of the difference between the transmitted wave (i.e., the reference wave) and the received wave, which has an FMCW wave.

[0048] The phase controller 5 scans the beam by changing the scanning phase amount φ(θ) given to the phase shifter 32 according to the illumination direction θ of the beam from the OPA3. The scanning phase amount φ(θ) is a vector consisting of phase shifts φ1 to φK set for each element of the antenna array 33. The scanning phase amount φ(θ) is a theoretically determined value based on the element configuration and the illumination direction θ of the beam.

[0049] The phase controller 5 provides the phase shifter 32 with a value that corrects the scan phase amount φ(θ) using the phase adjustment amount ψ supplied from the signal processing unit 7. The phase adjustment amount ψ is a vector consisting of adjustment amounts ψ1 to ψK set for each element. The phase adjustment amount ψ is an adjustment amount used to eliminate phase errors caused by three-dimensional changes in the configuration of the antenna array 33 due to deformation of the substrate on which the OPA3 is mounted.

[0050] like Figure 1 As shown, the monitoring light-receiving unit 6 is positioned within the range of the beam illumination direction controllable by the OPA3 and is located outside the FOV. Specifically, it is provided on the inner wall surface of the front wall where the opening 11 is formed in the frame 10. The monitoring light-receiving unit 6 is, for example, a PD array in which multiple photodiodes (hereinafter, PDs) are arranged in one or two dimensions.

[0051] The signal processing unit 7 includes a microcomputer with a CPU 71 and a semiconductor memory (hereinafter, memory) 72, such as ROM or RAM. The signal processing unit 7 performs at least normal processing and correction processing. In addition to the programs used to perform normal processing and correction processing, the memory 72 stores at least the design values ​​and check sheets (hereinafter, LUTs) of the beam profile used for correction processing.

[0052] [1-2. Beam Profile]

[0053] The beam profile is information representing the characteristics of the beam formed by the OPA3. The beam profile may also include at least one of the beam spread angle and the offset of the beam illumination direction. The beam profile has an error E relative to the original design value due to thermal deformation of the PIC substrate on which the OPA3 is mounted. The error E tends to vary depending on the amount and direction of deformation.

[0054] Specifically, such as Figure 4 As shown, the beam spread angle increases and the offset of the beam illumination direction (i.e., the center direction of the main lobe) also increases with the increase of deformation.

[0055] In addition, such as Figure 5 As shown, when the left end of the PIC substrate deforms in the positive direction from the reference plane corresponding to the design value, and when the right end of the PIC substrate deforms in the negative direction from the reference plane, the irradiation direction shifts to the right. When the right end of the PIC substrate deforms in the positive direction from the reference plane, and when the left end of the PIC substrate deforms in the negative direction from the reference plane, the irradiation direction shifts to the left.

[0056] The LUT is created using the tendency of the error E in the beam profile. Specifically, it has a correspondence between the error E and the correction amount Δψ used to update the phase adjustment amount ψ. In addition, four different LUTs are prepared based on the combination of the direction of deviation from the illumination direction (i.e., whether it is to the right or to the left) and the deformation mode (i.e., whether it is in the positive or negative direction).

[0057] [1-3. Processing]

[0058] use Figure 6 The flowchart explains the normal processing performed by the signal processing unit 7.

[0059] Normal processing is performed repeatedly according to a pre-set normal processing cycle.

[0060] In S110, the signal processing unit 7 outputs the phase adjustment amount ψ to the phase controller 5. The phase adjustment amount ψ uses the value last updated through correction processing. If a preset allowable time has elapsed since the most recent correction processing, the phase adjustment amount ψ can also be set to 0.

[0061] In the next step S120, the signal processing unit 7 causes the light source 2 to emit light during the time required for scanning the FOV.

[0062] At this time, the phase controller 5 changes the scanning phase quantity φ(θ) sequentially while supplying the phase shift quantity φ(θ)+ψ, obtained by adding the phase adjustment quantity ψ to the scanning phase quantity φ(θ), to the phase shifter 32. As a result, a beam of light illuminating the scanning FOV is emitted from the OPA3.

[0063] In the next step S130, the signal processing unit 7 acquires the light-receiving signal from the detector 4, performs ranging processing based on the light-receiving signal using known methods in the FMCW radar, and ends the processing.

[0064] Next, use Figure 7 The flowchart illustrates the correction process performed by the signal processing unit 7.

[0065] Whenever normal processing is performed, correction processing is performed before or after normal processing. Correction processing can also be performed every correction processing cycle that is set to be longer than the normal processing cycle, or whenever optical scanner 1 is started.

[0066] In S210, the signal processing unit 7 instructs the phase controller 5 to supply the phase shift amount φ(θh+ψ) for correction to the phase shifter 32. θh is the azimuth angle of the light receiving unit 6 used for monitoring when observing from the radiation center of the OPA3, and is a fixed value determined by the structure of the optical scanner 1. ψ is the currently set phase adjustment amount.

[0067] In the next step S220, the signal processing unit 7 causes the light source 2 to emit light. If the light source 2 emits light, a beam of light is irradiated from the OPA3 onto the monitoring light receiving unit 6.

[0068] In the following S230, the signal processing unit 7 acquires a monitoring light-receiving signal from the monitoring light-receiving unit 6, and detects the beam profile of the beam irradiated from the OPA3 based on the acquired monitoring light-receiving signal. Specifically, it detects the beam spread angle and the offset of the beam irradiation direction.

[0069] In the following S240, the signal processing unit 7 calculates the error E of the detected value relative to the design value of the beam profile in S230. The error E is expressed by the absolute value of the offset and by the sign of the offset. Therefore, the error E can be calculated directly using the offset of the illumination direction as the detected value, or it can be calculated using the value obtained by combining the beam spread angle with the sign of the offset of the beam illumination direction (i.e., the direction of the offset) as the detected value.

[0070] In the next step S250, it is determined whether the absolute value of the error E calculated in S240, |E|, is less than the preset threshold Eth. If |E| < Eth, the processing ends; if |E| ≥ Eth, the processing moves to S260.

[0071] In S260, the signal processing unit 7 determines whether the termination condition is met. The termination condition may be, for example, whether the number of times the processing can be repeated has reached an upper limit. If the termination condition is met, the signal processing unit 7 terminates the processing; if the termination condition is not met, the signal processing unit 7 moves the processing to S270.

[0072] In S270, the signal processing unit 7 determines whether the number of repetitions of the processing in S210 to S250 in this correction cycle is the first time. If it is the first time, the processing is moved to S280. If it is the second time or later, the processing is moved to S290.

[0073] In S280, the signal processing unit 7 initializes the deformation setting value, indicating whether the deformation of the PIC substrate, which is the cause of the error E, is a positive or negative deformation, and proceeds to S310. During the initialization of the deformation setting value, it is set to the same value as the deformation setting value finally set when the previous correction process was initiated. If a preset allowable time has elapsed since the previous correction process, the value can be set to any value.

[0074] In S290, the signal processing unit 7 compares the error |E| calculated in S240 with the error |E| calculated in the previous repetition cycle in S240, and determines whether the error |E| has increased. If the error |E| has increased, the signal processing unit 7 moves the processing to S300; if it has not increased, the signal processing unit 7 moves the processing to S310.

[0075] In S300, the signal processing unit 7 reverses the deformation setting value and advances the processing to S310.

[0076] In S310, the signal processing unit 7 uses a LUT corresponding to the deformation setting value to calculate a correction amount Δψ to bring the error E calculated in S240 close to zero. It then updates the phase adjustment amount ψ by adding the calculated correction amount Δψ to the current value of the phase adjustment amount ψ, and returns the processing to S210. Alternatively, the update of the phase adjustment amount ψ can be performed using a calculation formula instead of a LUT.

[0077] Here, the processing in S270 to S310 means the following: that is, as... Figure 5As shown, since there are cases where the deformation mode cannot be distinguished solely by the error E of the beam profile, firstly, for example, assuming the left end deforms in the positive direction, the phase adjustment amount ψ is updated using the LUT corresponding to this situation. Then, if the result of repeating the process from S210 to S250 is a decrease in error |E|, it is inferred that the assumption of the deformation mode is correct, and therefore the phase adjustment amount ψ is repeatedly updated using the same LUT. If the result of repeating the process from S210 to S250 is an increase in error |E|, it is inferred that the assumption of the deformation mode is incorrect, and therefore the assumption of the deformation mode is reversed, that is, assuming the right end deforms in the negative direction, the phase adjustment amount ψ is updated using the LUT corresponding to this situation.

[0078] [1-3. Effects]

[0079] According to the first embodiment described in detail above, the following effects are achieved.

[0080] (1a) In the optical scanner 1, the illumination light from the OPA3 is directly detected by the monitoring light-receiving unit 6, and the phase of the light propagating in space is directly fed back to the phase adjustment amount ψ given to the phase shifter 32 of the OPA3. Therefore, it is possible to compensate not only for errors caused by factors within the circuitry mounted on the PIC substrate, such as deviations in the characteristics between the light source 2 and the waveguide of the antenna array 3, but also for errors caused by factors outside the circuitry, such as deformation of the PIC substrate. As a result, it is possible to achieve high-precision optimization of the beam profile and the scanning of the beam.

[0081] (1b) In the optical scanner 1, different LUTs are prepared according to the deformation mode of the PIC substrate, and the correction amount Δψ is calculated using an arbitrarily selected LUT. Furthermore, the appropriate LUT is determined to be selected based on the increase or decrease of the error |E| after updating the phase adjustment amount ψ with the calculated correction amount Δψ, i.e., whether the inference of the deformation mode is correct. Therefore, in the optical scanner 1, the deformation mode of the PIC substrate, which is difficult to determine from the beam profile detected by the monitoring light-receiving signal, can be inferred, and thus the phase adjustment amount ψ can be updated accurately.

[0082] [2. Second Implementation]

[0083] [2-1. Differences from the first embodiment]

[0084] Since the basic structure of the second embodiment is the same as that of the first embodiment, the differences will be described below. Furthermore, the same reference numerals as in the first embodiment denote the same structures, as described above.

[0085] In the second embodiment, the method for calculating the phase adjustment amount ψ is different from that in the first embodiment.

[0086] like Figure 8 As shown, the optical scanner 1a of this embodiment, in addition to the structure of the optical scanner 1 of the first embodiment, also includes a phase monitor 8.

[0087] Phase monitor 8 independently detects the phase of the light supplied to each element forming antenna array 33.

[0088] In addition to using the detection signal from the monitoring light receiving unit 6, the signal processing unit 7 also uses the detection signal from the phase monitor 8 to calculate the phase adjustment amount ψ.

[0089] [2-2. Processing]

[0090] use Figure 9 The flowchart shows that the signal processing unit 7 of the second embodiment is replaced by the signal processing unit 7 of the second embodiment. Figure 6 The usual procedures performed as shown are explained.

[0091] In step S115, the signal processing unit 7 outputs the sum of the external factor adjustment amount ψa and the internal factor adjustment amount ψb as the phase adjustment amount ψ to the phase controller 5. ψa and ψb use the values ​​last updated through normal processing or correction processing. The external factor adjustment amount ψa can also be set to 0 after the final update, provided that a preset allowable time has elapsed.

[0092] The following processes, S120 to S130, are the same as in the first embodiment, so the description is omitted.

[0093] In the next step S140, the signal processing unit 7 acquires the detection signal from the phase monitor 8 and, based on the acquired detection signal, determines whether there is a shift (hereinafter, phase shift) in the phase difference of the light supplied to each element that deviates from the design value. If the signal processing unit 7 determines that a phase shift exists, it proceeds to S150; if it determines that no phase shift exists, it ends the processing.

[0094] In S150, the signal processing unit 7 updates the intrinsic factor adjustment amount ψb by calculating the correction amount Δψb used to make the phase difference of the light supplied to each element consistent with the design value (i.e., to make the phase shift 0), and adds it to the current intrinsic factor adjustment amount ψb, and then ends the processing.

[0095] Next, use Figure 10 The flowchart is replaced by the signal processing unit 7 of the second embodiment. Figure 7 The correction process performed as shown will be explained.

[0096] In S215, the signal processing unit 7 instructs the phase controller 5 to supply the correction phase shift φ(θh+ψ) to the phase shifter 32. θh is the azimuth angle of the monitoring light-receiving unit 6 when observed from the radiation center of the OPA3, and is a fixed value determined by the structure of the optical scanner 1a. ψ is the sum of the external factor adjustment amount ψa and the internal factor adjustment amount ψb.

[0097] The following processes S220 to S240 are the same as those in the first embodiment, so the description is omitted.

[0098] In the following S242, the process is the same as in S140. The signal processing unit 7 acquires the detection signal from the phase monitor 8 and determines whether a phase shift exists based on the acquired detection signal. If the signal processing unit 7 determines that a phase shift exists, the process proceeds to S244; if it determines that no phase shift exists, the process proceeds to S250.

[0099] In S244, the same as in S150, the signal processing unit 7 calculates the correction amount Δψb, uses the correction amount Δψb to update the intrinsic factor adjustment amount ψb, and advances the processing to S250.

[0100] The processing in S250 to S310 is the same as in the first embodiment, so the description is omitted. In the description of S250 to S310, the phase adjustment amount ψ is replaced with the external factor adjustment amount ψa.

[0101] [2-3. Effects]

[0102] According to the second embodiment described in detail above, the effects of the first embodiment (1a) and (1b) described above are achieved, and the following effects are achieved.

[0103] (2a) In the optical scanner 1a, the phase adjustment amount ψ is calculated by separating it into external factor adjustment amount ψa and internal factor adjustment amount ψb. Therefore, the phase adjustment amount ψ can be calculated with higher accuracy, which can improve the control accuracy of OPA3.

[0104] [3. Other Implementation Methods]

[0105] The embodiments of this disclosure have been described above, but this disclosure is not limited to the above embodiments and can be modified and implemented in various ways.

[0106] (3a) In the above embodiment, the monitoring light-receiving part 6 is disposed on the inner wall surface of the front wall of the frame 10 where the opening 11 is formed, but it can also be disposed as follows: Figure 11 As shown, it is located on the inner wall surface of the side wall of the frame 10.

[0107] (3b) In the above embodiment, a monitoring light-receiving part 6 is arranged at a position that can face the main lobe, but the arrangement of the monitoring light-receiving part 6 is not limited to a position that can face the main lobe. For example, such as Figure 11 As shown, the monitoring light-receiving unit 6 can also be arranged at the position illuminated by the grating lobe when the main lobe is in a predetermined direction (e.g., the frontal direction). In this case, beam control without correction processing is possible.

[0108] (3c) In the above embodiment, a monitoring light-receiving unit 6 is provided at a position where it directly receives the illumination light from the OPE3. However, a reflector 9 may also be provided at a position where the illumination light from the OPE3 shines, and the monitoring light-receiving unit 6 may be provided at a position where it receives the reflected light reflected by the reflector 9. In this case, the monitoring light-receiving unit 6 may also be as follows: Figure 12 As shown, it is configured on the side wall of the frame 10, or as... Figure 13 As shown, it is positioned on the same wall surface as where OPA3 is located. By providing the reflector 9, the flexibility in the placement of the monitoring light-receiving unit 6 can be increased.

[0109] (3d) The signal processing unit 7 and its method described in this disclosure may also be implemented by a special-purpose computer consisting of a processor and a memory programmed to perform one or more functions embodied in a computer program. Alternatively, the signal processing unit 7 and its method described in this disclosure may also be implemented by a special-purpose computer consisting of a processor composed of one or more special-purpose hardware logic circuits. Or, the signal processing unit 7 and its method described in this disclosure may also be implemented by one or more special-purpose computers consisting of a processor and a memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium. The method for implementing the functions of each part included in the signal processing unit 7 does not necessarily need to include software, and all its functions may be implemented using one or more hardware components.

[0110] (3e) Multiple functions of one component in the above embodiments can be achieved through multiple components, or one function of one component can be achieved through multiple components. Alternatively, multiple functions of multiple components can be achieved through one component, or one function achieved by multiple components can be achieved through one component. Furthermore, a portion of the structure of the above embodiments can be omitted. Additionally, at least a portion of the structure of the above embodiments can be added to the structure of other above embodiments, or at least a portion of the structure of the above embodiments can replace the structure of other above embodiments.

[0111] (3f) In addition to the optical scanner described above, this disclosure can also be implemented in various forms such as a system that includes the optical scanner, a program for enabling a computer to function as the signal processing unit of the optical scanner, a non-transitional physical recording medium such as a semiconductor memory that records the program, and a phase adjustment method for OPA.

Claims

1. An optical scanner, comprising: light source; An optical phased array is configured to scan a light beam by independently controlling the phase of multiple branched beams formed from light supplied from the aforementioned light source using scanning phase quantities and radiating them from an antenna array having multiple antenna elements. The light-receiving unit for monitoring is configured to receive light emitted from the aforementioned optical phased array; as well as The signal processing unit is configured to detect the characteristics of the light beam based on the detection results from the monitoring light receiving unit, and generate a phase adjustment amount to correct the scanning phase quantity so that the detected value of the characteristics matches the pre-prepared design value. The signal processing unit uses at least one of the beam spread angle and the offset of the beam illumination direction as a characteristic of the beam.

2. The optical scanner according to claim 1, wherein, The aforementioned light-receiving unit for monitoring is positioned at the location that receives the grating lobes formed by the aforementioned optical phased array.

3. The optical scanner according to claim 1, wherein, The aforementioned light-receiving unit for monitoring is positioned outside the scanning range of the aforementioned optical phased array.

4. The optical scanner according to claim 1, wherein, It also includes a phase monitor, which is configured to independently detect the phase of each of the multiple branch beams. The signal processing unit is configured to set the result of adding the intrinsic factor adjustment amount to the extrinsic factor adjustment amount as the phase adjustment amount. The intrinsic factor adjustment amount is calculated based on the detection results in the phase monitor, taking into account the deviation of the characteristics between the waveguides that propagate the multiple branch lights respectively. The extrinsic factor adjustment amount is calculated based on the detection results in the monitoring light receiving unit, taking into account the deformation of the surface on which the antenna element is disposed.

5. The optical scanner according to claim 1, wherein, The signal processing unit is configured to calculate the correction amount for updating the phase adjustment amount based on the error of the detected value relative to the design value related to the characteristics of the beam, using a pre-prepared checklist.

6. The optical scanner according to claim 1, wherein, The aforementioned light source and the aforementioned optical phased array are mounted on the same substrate.

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