The present disclosure provides a compressed ultrafast imaging velocity interferometer system for any reflector, comprising a light source and target system, an etalon interference system, a compressed ultrafast imaging system, a timing control system and a data processing system. An imaging device in the traditional imaging velocity interferometer system for any reflector is replaced by a compressed ultrafast imaging system, a compressed ultrafast Photography (CUP) is introduced in an imaging process, multi-frame images, i.e. three-dimensional images for two-dimensional space and one-dimensional time, are reconstructed via a single measurement by a CUP-VISAR two-dimensional ultrafast dynamic image imaging, a complete dynamic process of a two-dimensional interference fringes image is restored, and spatiotemporal evolution information of a shock wave is effectively acquired, improving an imaging performance of the imaging velocity interferometer system for any reflector in dimension, and achieving a goal that could not be achieved before.

Optical measuring apparatus includes: a light source irradiating an object to be measured; a splitter splitting transmitted light or reflected light from the object to be measured; a phase changer changing a phase of a first light which is one of the lights split; a phase fixer maintaining a phase of a second light which is the other light split; a multiplexer multiplexing lights output from the phase changer and the phase fixer; a detector detecting the light (interference image) output from the multiplexer; and a controller that extracts a reference point from the interference image, when a displacement of the reference point is detected, corrects a luminance value for each pixel of the interference images in accordance with a displacement of the object to be measured indicated by a displacement of the reference point, constructs an interferogram based on the luminance value for each pixel of the interference images after the correction.

A holographic interferometer, comprising: an imaging device capturing an interference pattern created by at least two polarized light beams; a structured phase retardation element located in an optical path of at least one polarized light beam of the at least two polarized light beams; and a polarizer located between the imaging device and the structured phase retardation element, the polarizer projects each polarization of each of the at least two polarized light beams on a single axis to create the interference pattern on the imaging device.

An interferometer having a fundamental beam generator, a first second harmonic generator, a waveplate, a second second harmonic generator, a harmonic separator, and a polarizing beam splitter, mounted uniaxially, (i.e., the components are aligned along one optical axis), wherein the interferometer is adapted to change a diameter of a beam to match a diameter of a sample, and to change the diameter of the beam back to its original diameter.

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

Self-mixed interferometer (SMI) devices and techniques are described for measuring depth and/or velocity of objects. The SMI devices and techniques may be used for eye-tracking. A light source of an SMI sensor emits coherent light that is directed to a target location with a scanning module. One or more SMI signals are measured. The one or more SMI signals are generated by the SMI sensor in response to feedback light received from the target location. The feedback light is a portion of the coherent light that illuminated the target location.

Self-mixed interferometer (SMI) devices and techniques are described for measuring depth and/or velocity of objects. The SMI devices and techniques may be used for eye-tracking. A light source of an SMI sensor emits coherent light that is directed to a target location with a scanning module. One or more SMI signals are measured. The one or more SMI signals are generated by the SMI sensor in response to feedback light received from the target location. The feedback light is a portion of the coherent light that illuminated the target location.

A self-referencing interferometer (SRI) system for an alignment sensor apparatus includes a first prism and a second prism. The first prism has an input surface for an incident beam. The second prism is coupled to the first prism and has an output surface for a recombined beam. The recombined beam includes a first image and a second image rotated by 180 degrees with respect to the first image. The first and second prisms are identical in shape. A dual self-referencing interferometer (DSRI) system for an alignment sensor apparatus includes a first prism assembly having an input surface for a first incident beam and a second incident beam, and a second prism assembly coupled to the first prism assembly and having an output surface for a first recombined beam and a second recombined beam. The first and second prism assemblies are identical in shape.

A self-referencing interferometer (SRI) system for an alignment sensor apparatus includes a first prism and a second prism. The first prism has an input surface for an incident beam. The second prism is coupled to the first prism and has an output surface for a recombined beam. The recombined beam includes a first image and a second image rotated by 180 degrees with respect to the first image. The first and second prisms are identical in shape. A dual self-referencing interferometer (DSRI) system for an alignment sensor apparatus includes a first prism assembly having an input surface for a first incident beam and a second incident beam, and a second prism assembly coupled to the first prism assembly and having an output surface for a first recombined beam and a second recombined beam. The first and second prism assemblies are identical in shape.