159 results about "Optical path length" patented technology

The invention relates to the technical field of optical imaging, and discloses an AR optical projection machine and an optical display system, the projection machine comprises a projection lens group, a color combination prism assembly and a three-color display array; the projection lens group comprises a diaphragm STO, a first lens, a second lens, a third lens and a fourth lens. The color combination prism assembly comprises a plurality of prisms which are glued with one another, and a film coating structure which is used for reflecting red light and blue light and transmitting green light is arranged on each prism; the three-color display array comprises three display chips; wherein the FOV (field of view) of the AR optical projection machine is greater than or equal to 30 degrees and less than or equal to 40 degrees; the ratio of the total optical length TTL of the AR optical projection machine to the effective focal length f of the system meets the condition that TTL / f is larger than or equal to 5.0 and smaller than or equal to 7. The field angle of the system is limited within the range of 30-40 degrees, the ratio of the total optical length TTL to the effective focal length f is kept within 5.0-7.7, an imaging field meeting the AR application requirement can be obtained within the limited optical path length, meanwhile, the overall compactness of the optical system is considered, and the optical system can be more easily integrated into small-size near-to-eye display equipment.

The utility model discloses a thulium-doped fiber laser based on a composite cavity structure. The thulium-doped fiber laser comprises a pumping source, a thulium-doped gain active fiber, a high-reflectivity fiber grating HR, a first low-reflectivity fiber grating OC1 and a second low-reflectivity fiber grating OC2, the self-pulse effect is inhibited by adopting a composite resonant structure, so that stable 2-micron fiber laser output is obtained; the overall optical path length is short, and self-pulse suppression can be more effectively achieved under the condition that the overall optical path length is short.

The invention discloses an optical fiber connector end face defect detection method and system based on a mixed attention mechanism and dynamic enhancement, and belongs to the technical field of industrial visual inspection. According to the method, the zero optical path difference position of a white light interference curve is obtained through quadratic Gaussian function fitting, and the sensitivity to tiny defect textures is enhanced in cooperation with a multi-dimensional mixed attention mechanism, channel attention and space attention; dynamic adaptive data enhancement is provided, an enhancement strategy is adjusted in real time based on a model training state, and sample diversity is optimized; and a layered pruning and dynamic quantification scheme is designed for edge computing equipment, so that high-precision real-time detection is realized, and the method has certain reference significance in surface defect detection application in the field of precision manufacturing.

The invention discloses a two-photon N00N quantum state intelligent regulation and control device and method, and the device comprises an intelligent regulation and control module, and an entangled photon pair generation module, an HOM interferometer and a data collection module which are connected in sequence, and the entangled photon pair generation module transmits polarized orthogonal entangled photon pairs to two light paths in the HOM interferometer respectively; the data acquisition module is used for detecting and counting photons output by the two light paths respectively; the intelligent regulation and control module controls the first electric control time delay line on one light path and the electric control polarization controller on the corresponding light path so as to regulate the light path difference of the two light paths and the polarization state of photons output by the corresponding light path; every time control is completed, a second electric control time delay line on the other light path is controlled to carry out time delay scanning according to a set rule, and a coincidence counting rate and HOM visibility are obtained; and according to the coincidence counting rate and the HOM visibility, determining whether the two-photon N00N quantum state generated under the control is good or bad. According to the invention, intelligent regulation and control of the two-photon N00N quantum state quality can be realized.

An optical displacement sensor comprises a reflective surface and one or more diffraction gratings which, together with the reflective surface, each define a respective interferometric arrangement. The reflective surface is moveable relative to the diffraction grating(s) or vice versa. Light from a light source propagates via the interferometric arrangement(s) to produce an interference pattern at a respective set of photo detectors. Each interference pattern depends on the separation between the reflective surface and the respective grating. A collimating optical arrangement at least partially collimates the light between the light source and the diffraction grating(s). For the or each interferometric arrangement, when the reflective surface or the diffraction grating is in a zero-displacement position, the optical path length L of the light propagating between the diffraction grating and the reflective surface satisfies the relationship:L=Tz⁢n2,to within 20% ofTz2, where n is an integer; where Tz is the Talbot length, defined by:Tz=λ1-1-λ2p2,where λ is the wavelength of the light, and where p is the grating period of the respective diffraction grating.

Provided is a pulse width expansion device for expanding the pulse width of a pulsed laser beam, the pulse width expansion device including a first optical pulse stretcher, a second optical pulse stretcher, a third optical pulse stretcher, and a fourth optical pulse stretcher disposed on the optical path of the pulsed laser beam, the first optical pulse stretcher, the second optical pulse stretcher, the third optical pulse stretcher, and the fourth optical pulse stretcher being disposed on the optical path of the pulsed laser beam. The optical path length of the delay optical path of the first optical pulse stretcher is L1, the optical path length of the delay optical path of the second optical pulse stretcher is L2, the optical path length of the delay optical path of the third optical pulse stretcher is L3, and the optical path length of the delay optical path of the fourth optical pulse stretcher is L4. When n is an integer of 2 or more, L2 is an integer multiple of 2 or more of L1, L3 satisfies (n-0. 75) * L1 < = L3 < = (n-0.25) * L1, and L4 satisfies (n-0.25) * L1 < = L4 < = (n + 0.25) * L1.

The present invention provides an interference measurement method and apparatus that can appropriately measure the physical properties of a sample in a non-contact manner. [Solution] The interference measurement method using the interference measurement device 1 includes: a first step of obtaining a first interference waveform W1 for each optical path length difference in the first state by performing measurements while changing the optical path length difference between the first optical path P1 and the second optical path P2 in a first state in which no sample S is placed in the second optical path P2; a second step of converting the first interference waveform W1 into a first electric field amplitude waveform WE1; a third step of obtaining a second interference waveform W2 for each optical path length difference in the second state by performing measurements while changing the optical path length difference in a second state in which a sample S is placed in the second optical path P2; a fourth step of converting the second interference waveform W2 into a second electric field amplitude waveform WE2; and a fifth step of obtaining measured values ​​regarding the physical properties of the sample S based on the electric field amplitudes corresponding to the peaks of the first electric field amplitude waveform WE1 and the second electric field amplitude waveform WE2, respectively.

A laser device includes an oscillator outputting pulse laser light; an amplifier amplifying the pulse laser light; an optical pulse stretcher extending a pulse width of the pulse laser light; a beam divergence angle adjuster including an upstream lens arranged on an optical path of the pulse laser light, a downstream lens arranged downstream of the upstream lens, and an optical path length changing mechanism for changing an inter-lens optical path length between the upstream lens and the downstream lens; and a processor controlling the beam divergence angle adjuster and obtaining a repetition frequency or a duty of the pulse laser light, and to change, when the repetition frequency or the duty changes by a preset threshold or more, the inter-lens optical path length so that the beam divergence angle of the extended pulse laser light becomes small in accordance with the repetition frequency or the duty after the change.

An optical computing system includes: an intensity modulation device group including at least two intensity modulation devices, each of which includes modulation cells, wherein each of the modulation cells of each of the intensity modulation devices carries out intensity modulation with respect to carrier light in accordance with one of signals to generate a signal light beam, and each of the signals corresponds to each of the intensity modulation devices; and a light diffraction element including diffraction cells having respective thicknesses or refractive indices set independently of each other, wherein each of the diffraction cells receives the signal light beam from each of the modulation cells of each of the intensity modulation devices corresponding to each of the diffraction cells, and by causing signal light beams to have respective different optical path lengths to the light diffraction element, the signal light beams have respective different phases.

The invention provides a double-pulse laser engraving method and device, and relates to the technical field of laser engraving, the double-pulse laser engraving method and device are used for engraving a gravure forme.The engraving method comprises the steps that the wavelength of femtosecond pulse laser and the wavelength of picosecond pulse laser are determined; determining the pulse delay of the femtosecond pulse laser and the picosecond pulse laser; determining a to-be-engraved area of the gravure plate; adjusting the optical path length of the femtosecond pulse laser and / or the picosecond pulse laser according to the pulse delay; synthesizing the femtosecond pulse laser and the picosecond pulse laser into double-pulse laser by using a polarization beam splitting cube; and ablating the to-be-engraved area according to the double-pulse laser. The femtosecond pulse laser is short in wavelength and high in energy, so that a to-be-engraved area can be pre-ablated quickly, when ungasified plasma is formed in the pre-ablated area, the picosecond pulse laser is used for performing secondary ablation on the pre-ablated area, the machining quality of the gravure plate can be guaranteed, the area of a heat affected area can be controlled, and the etching precision of an etched pattern can be improved.

Provided is a self-injection locking type laser device in which variations in environmental changes, optical path length, and resonator length are less likely to occur. The self-injection locking type laser device includes a first base plate, a second base plate, a temperature adjustment element disposed between the first base plate and the second base plate, a semiconductor laser light source disposed on the first base plate, a reference resonator disposed on the first base plate, located on an optical path of laser light emitted from the semiconductor laser light source, and including at least a first mirror and a second mirror for providing optical feedback to the semiconductor laser light source, a first cover covering the semiconductor laser light source and the reference resonator and in contact with the first base plate, and a second cover covering the first cover and in contact with the second base plate.

To provide a sensitivity measuring device and a sensitivity measuring method capable of measuring spectral sensitivity distribution of a light receiving element to be measured in a short time.SOLUTION: The sensitivity measurement device includes a light source, an optical system, a light collection mechanism, a position adjustment mechanism, a measurement unit, and an analysis unit. The optical system is configured to generate an interference wave by splitting light from a light source into two beams and causing the two beams to interfere with each other, and includes an optical path length difference changing mechanism configured to change an optical path length difference. The condensing mechanism condenses the interference wave at an irradiation position on the light receiving surface of the measured light receiving element. The position adjustment mechanism changes an irradiation position of the interference wave in a direction along the light receiving surface. The measurement unit controls the irradiation position and acquires a signal obtained by converting the interference wave from the light receiving element to be measured. The analysis unit calculates a component of the signal of each wavelength by Fourier transform of an interferogram obtained from the optical path length difference changed by the optical path length difference changing mechanism and the intensity of the signal measured by the measurement unit.SELECTED DRAWING: Figure 1

An interference measuring device 1A comprises a light source 10, an interference optical system 20A, a photomultiplier tube 30, an interference intensity measuring unit 40, a unit 50 for calculating the electric field amplitude, and an analysis unit 60. The light source 10 emits light in a band (a light band containing terahertz waves) to which the photomultiplier tube 30 is sensitive. The photomultiplier tube 30 is sensitive in a light band containing terahertz waves and outputs an electrical signal with a value corresponding to the intensity of the incident light.The unit 50 for calculating the electric field amplitude converts a value of intensity V of interference light, measured by the interference intensity measuring unit 40, into a value of electric field amplitude E, based on a relationship between a value of the electric field amplitude of light incident on the photomultiplier tube 30 and a value of the electrical signal output by the photomultiplier tube 30. It obtains the value of the electric field amplitude E of the interference light for each value of a time difference Δt, which corresponds to an optical path length difference Δd. Thus, an interference measuring device and an interference measurement method are realized that can perform Fourier spectroscopy by interference measurement using a terahertz wave quickly and accurately.

The dual-mode optical lens comprises a positive lens, a negative lens, a first turning mirror, a second turning mirror, a third turning mirror, a fourth turning mirror, an optical sensor and a machine shell, a linear sliding table is fixedly installed in the machine shell, and a moving part of the linear sliding table is in transmission connection with an installation frame; a second light hole is formed in one side of the top end of the mounting frame, a first light hole is formed in the bottom end of the other side of the mounting frame, the positive lens, the negative lens and the second light hole are located on the same horizontal line, and the first light hole and the light sensor are located on the same horizontal line; through the combination of the negative lens and the positive lens, a long focal length is realized under a relatively short optical path length, a more compact distance is realized through the two small-incidence-angle plane turning mirrors, and the two plane reflecting mirrors are combined and inserted into an optical path between the positive lens and the negative lens, so that light rays do not pass through the negative lens, and the optical path is more compact. And a relative small focal length light path corresponding to the positive lens directly reaches the sensor.

The invention relates to an optical path length adjusting device of a micro spectrophotometer for measuring the optical property of light passing through a sample. The optical path length adjusting device of a spectrophotometer according to the present invention comprises: a housing; a cover arm mounted so as to be rotatable about a hinge shaft provided on one side of an upper portion of the housing; a cover arm retainer on which the free end of the cover arm rests in the closed state; a lower base irradiated with light transmitted from a lamp installed inside the housing through an optical fiber; the upper base is supported by the cover arm and is positioned above the lower base; a lower base moving device configured to vertically move the lower base relative to the upper base; the spectrograph is configured to receive the light which is irradiated on the lower base and passes through the light path through the optical fiber and analyze and display the measurement characteristics of the sample, and the opposite surfaces of the lower base and the upper base are in a non-parallel state. The light path length adjusting device of the micro spectrophotometer is simple in structure, so that high-precision absorbance measurement can be carried out in an ultra-high concentration range without precise control.

A biological sample analysis system (100) according to an embodiment includes a detection optical system (121), a focal point of which is set at a predetermined position in a container (C), an imaging unit (122), a light receiving surface of which is located at an image forming position of an image of light transmitted through the detection optical system (121), and an optical path length adjustment element (13) disposed on an optical path between the detection optical system (121) and the imaging unit (122) and in a part within an angle of view of the imaging unit (121).

The utility model discloses a femtosecond laser pulse compression device. The device comprises an amplifier, a half-wave plate and a transmission-type compression grating which are sequentially arranged along a light path, a first climbing mirror and a second climbing mirror are arranged on a diffraction light path on one side of the transmission-type compression grating, and a third climbing mirror and a leading-out reflector are arranged on a diffraction light path on the other side of the transmission-type compression grating; and a cylindrical lens group is arranged between the transmission-type compression grating and the first climbing mirror and the second climbing mirror. According to the technical scheme, a single grating is matched with a plurality of climbing mirrors to form a laser turn-back system, compression of laser pulses is completed under the condition that the size of the laser pulse compression device is greatly reduced through a simple structure, a large dispersion providing amount can be achieved within a short optical path length through further arrangement of a cylindrical lens set, and therefore the laser pulse compression device has the advantages of being simple in structure, convenient to operate and high in efficiency. The set size of the device is further reduced, the miniaturization design of the femtosecond laser pulse compression device is facilitated, and the cost is reduced.

The present invention discloses an adjustment mechanism for an infrared laser optical mirror, comprising a vacuum chamber, a translation adjustment unit, a rotation adjustment unit, and an optical mirror assembly. The translation adjustment unit comprises a horizontal adjustment unit and a vertical adjustment unit. The optical mirror assembly, the rotation adjustment unit, and the horizontal adjustment unit are all located within the vacuum chamber. In the present invention, four-dimensional adjustment of the optical mirror assembly can be achieved by providing the translation adjustment unit and the rotation adjustment unit. The rotation assembly and the horizontal adjustment unit, as well as the rotation assembly and the optical mirror assembly, are both provided with a rotational connection, and the rotation axis of the rotation assembly and the rotation axis of the optical mirror assembly are cross-connected, so that the two rotation axes of the pitch angle and the rolling glue intersect at the center of the optical mirror assembly. During rotational adjustment, no additional translation is generated and no other rotation is affected. The center position of the mirror surface remains unchanged, and the optical path length remains unchanged, greatly simplifying the adjustment process.

Wavefront measurement of a multi-core optical fiber is described. A multi-core optical fiber is configured to conduct radiation from a radiation source to a structure, such as a metrology target, in one or more layers of a patterned substrate, and to conduct diffracted and / or reflected radiation from the metrology target to a radiation sensor. The multi-core optical fiber has a length configured to facilitate placement of the radiation source and / or the radiation sensor in spaced locations relative to the patterned substrate. Optical path length differences between sets of fiber cores with reflectors in the multi-core optical fiber are determined for radiation of different wavelengths from the radiation source. The optical path length difference is determined based on a path length of reflected radiation that is incident on the radiation sensor after returning through the core set. The optical path length difference indicates wavefront distortion.

A depth extender for an imaging system includes an optical element having a radially correlated thickness deviation proportional to an oscillation function having a first envelope and a second envelope. The first envelope has an amplitude at each of a plurality of radial distances, the amplitude being substantially equal to the difference between: (i) a reference optical path length originating from a reference ray traveling in the radial distance within the object plane between a minimum and a maximum object distance, and (ii) the optical path length of a first ray traveling in the radial distance within the object plane at the minimum object distance. The second envelope has an amplitude at each radial distance substantially equal to the difference between: (i) the reference optical path length, and (ii) the optical path length of a second ray traveling in the radial distance within the object plane at the maximum object distance.

The light emitting device includes a first light emitting element and a second light emitting element formed on a substrate, and a first microlens and a second microlens. The first light emitting element includes a first light emitting layer and an optical resonant structure having a first optical path length, and the second light emitting element includes a second light emitting layer and an optical resonant structure having a second optical path length, the second optical path length being longer than the first optical path length. The area of the light-emitting region of the first light-emitting layer is defined as S1 ', where S1 is the area of the light-emitting region of the first light-emitting layer, and S1 is the area of the light-emitting region of the first light-emitting layer, where the light that has entered from the normal direction of the substrate and has passed through the first microlens enters the light-emitting region of the first light-emitting layer. The area of a region where light that has entered from the normal direction of the substrate and has passed through the second microlens enters the light-emitting region of the second light-emitting layer is defined as S2 ', and the area of the light-emitting region of the second light-emitting layer is defined as S2', then S1-S1 '< S2-S2'.

The projection exposure apparatus (10) comprises: a mask mark illumination light source (21) capable of irradiating a mask mark (MM) with exposure light itself or first alignment light (L1) having substantially the same wavelength as the exposure light; and an alignment unit (30) having a workpiece mark illumination light source (31) capable of irradiating a workpiece mark (WM) with second alignment light (L2) having a different wavelength from the exposure light, an imaging device (32), and an imaging optical system (40). The imaging optical system (40) comprises: a first dichroic prism (41) for synthesizing the first alignment light (L1) and light from the workpiece mark (WM) and emitting the resultant light to the imaging device (32); and an optical path length changing optical system (42) for branching and converging the first alignment light (L1) so that the optical positional relationships of the images (MMI) of the workpiece mark (WM) and the mask mark (MM) relative to the imaging device (32) are equal. Thus, a projection exposure apparatus and a projection exposure method capable of high-precision alignment even in a small-sized exposure area can be provided.

Full-color pixel arrangements for use in devices such as OLED displays are provided, in which multiple sub-pixels are configured to emit different colors of light, with each sub-pixel having a different optical path length than some or all of the other sub-pixels within the pixel.

A qubit decoding device (200) is configured to receive a photon having a qubit encoded with a property of the photon, the qubit decoding device (200) comprising a demodulation device (210). The demodulation device (210) comprises an optical modulator (212) configurable to randomly apply one of a plurality of modulation values ​​for decoding the qubit to the property of the photon, and an optical router (214, 414) for routing the photon according to the qubit. The qubit decoding device (200) further comprises an optical delay device (220), the optical delay device (220) comprising an optical combiner (222), a first optical path (224) from the optical router to the optical combiner, and a second optical path (226) from the optical router to the optical combiner. The second optical path (226) has an optical path length different from that of the first optical path to introduce a time delay between the optical paths. The qubit decoding device (200) further includes a detection device (230) configured to detect the photon and operable to determine whether the detected photon is delayed relative to a reference time and to determine the qubit based on the determined time delay.

A digital lithography system includes a light source configured to emit a light beam along an optical path toward a substrate via one or more optical elements. The digital lithography system further includes a digital micro-mirror device (DMD) configured to receive the light beam and form an output light beam. The output light beam is emitted along the optical path toward the substrate. The digital lithography system further includes an imaging device configured to capture an image of the substrate illuminated at least in part by the output light beam. A first optical path length corresponding to the DMD and a second optical path length corresponding to the imaging device are unequal.

A method for monitoring a subject using an optical physiological sensor system includes obtaining an optical property model of at least one biological tissue type to be monitored, the optical property model including definitions of static and dynamic components of transmitted optical power and a source-to-detector distance related to a normalized optical path length of an illumination source of the optical physiological sensor. The method also includes obtaining an indication of at least one physiological property of the subject from a wearable device worn by the subject, obtaining an indication of at least one physical variable from the wearable device worn by the subject, determining using the optical physiological model how the at least one physical variable affects the at least one physiological property, and determining a correction value for the physiological property based on the determination of how the at least one physical variable affects the at least one physiological property.

The present invention relates to a variable optical path ultra-large range liquid concentration measurement system and method. The system includes a light source module, a detection light module, a reference light module, a high-precision linear motion module, and a data analysis module. The light source module divides the light signal emitted by the light source into detection light and reference light; the detection light module detects the light signal absorbed by the liquid to be measured through a detection light path detector to obtain the detection light intensity; the high-precision linear motion module controls the detection light fiber to be inserted into the solution to be measured, and gradually moves within the optical path length interval with a set step size to achieve high-precision micron-level variable optical path length; the data analysis module corrects the detection light intensity through an optical signal fluctuation feedback correction method. Based on multiple sets of optical path lengths and the corrected detection light intensity, a least squares regression algorithm is used to fit the relationship between light intensity and optical path length to calculate the concentration value of the liquid to be measured. Compared with the prior art, the present invention has a larger concentration measurement range and more accurate and stable concentration measurement results.

Technologies for optical equalizers with metasurfaces are disclosed. In an illustrative embodiment, an optical equalizer can be formed from two metasurfaces. The metasurfaces reflect light in different directions depending on the spatial mode of the light. The metasurfaces can be used to change the optical path length of different modes of light from an optical input to an optical output, such as from an optical fiber to a photodiode. The optical equalizer can delay some modes of light relative to other modes, partially or fully compensating for mode dispersion in a multi-mode optical fiber.

Provided is a laser interferometer capable of suppressing the incidence of return light on a laser light source and capable of suppressing a decrease in the precision of demodulation of a sampling signal originating from a measurement object based on a light reception signal. The laser interferometer includes a laser light source; a collimator that generates collimated light; a light modulator that modulates the collimated light into reference light having different frequencies; and a light reception element that receives object light and the reference light and outputs a light reception signal, the light axis of the collimated light is set as a first light axis, the light axis of the return light is set as a second light axis when the return light is generated, the position at which the collimated light is generated is set as a reference position, when the offset width of the first light axis and the second light axis in the reference position is set as Δy, the effective diameter of the collimator is set as κ, the optical path length of the collimated light is set as R, the distance from the reference position to the light modulator is set as L, and the wavelength of the collimated light is set as λ, the following expression (A) is satisfied

A method and corresponding apparatus for determining an absolute optical distance between two reflective surfaces constituting an interference cavity, the method comprising: moving an illumination spot in a rear focal plane of an interferometer along a trajectory having a non-zero radial component relative to an optical axis, enabling the irradiation light spot to move along different radial positions of the track, and synchronously acquiring an image of an interference pattern of the interference cavity; and analyzing the image using one or more electronic processors to determine a functional correlation of a difference in optical path length (OPD) of the interference cavity and a radial position of the illumination spot, and extracting an absolute optical distance between the two reflective surfaces based on the determined functional correlation.