An optical device includes: a light source that emits laser light; an optical waveguide element positioned on the optical path of the laser light; a first member positioned on the optical path, and has a bottom surface that faces the optical waveguide element, and a side surface that is rotationally symmetric about the optical path; and a control circuit. The optical waveguide element includes: a first grating that includes a plurality of portions arranged in the radial direction and having mutually different refractive indices, and that causes a portion of the laser light that is incident to be propagated in the radial direction within the optical waveguide element; and a second grating that includes a plurality of portions arranged outside the first grating, arranged in the radial direction, and having mutually different refractive indices, and that causes light to be emitted from the optical waveguide element.

A method of operating a light detection and ranging (LIDAR) system is provided that includes generating a beam of co-propagating, cross-polarized light using a first polarizing beam splitter; and determining a material characteristic or orientation of a target using the co-propagating, cross-polarized light.

A quantitative phase microscopy (QPM) system and methods are provided for sample imaging and metrology in both transmissive and reflective modes. The QPM system includes a first illuminating beam propagating along a transmission-mode path and a second illuminating beam propagating along a reflection-mode path, a microscope objective lens disposed in the reflection-mode path, and a common-path interferometer comprising a diffraction grating, a Fourier lens, a pinhole, and a 2f system lens to collimate the reference beam and the imaging beam such that the collimated reference beam and imaging beam interfere with each other to form an interferogram at a final image plane.

An optical device includes a spatial light modulator configured to project image light, a diffractive lens, and a polarization-selective reflector. The spatial light modulator defines an optical axis. The diffractive lens is positioned to receive the image light from the spatial light modulator. The polarization-selective reflector is positioned to receive the image light from the diffractive lens. The polarization-selective reflector having a polarization-selective reflective surface in an orientation that is non-perpendicular to the optical axis of the spatial light modulator.

An optical apparatus includes a deflection unit configured to deflect illumination light from a light source and to deflect reflected light from the object, and a light guide unit configured to guide the illumination light to the deflection unit and to guide the reflected light from the deflection unit to a light receiving unit. The light guide unit includes first and second passage areas, and a reflective area. The illumination light is branched into first and second illumination lights by the light guide unit. The first illumination light is emitted from the first passage area and the second illumination light is emitted from the second passage area so that an emission direction of the first illumination light and that of the second illumination light are not parallel to each other, and then the first illumination light and the second illumination light enter the deflection unit.

Provided is a waveguide-type display device including a waveguide, an input coupler provided on the waveguide and configured to transmit an image to travel into the waveguide, an output coupler provided on the waveguide and configured to output the image traveling in the waveguide to an outside of the waveguide, and a field-of-view (FOV) expander configured to output an image having an expanded FOV by deflecting and outputting the image output from the output coupler in a certain direction based on polarization characteristics of the image.

A laser interferometer that includes a light source configured to emit laser light, an optical divider configured to divide the laser light into a first optical path and a second optical path, an optical modulator being provided on the first optical path or the second optical path, including an oscillator that oscillates when a current is applied, and being configured to modulate the laser light by using the oscillator, a photoreceptor configured to receive the laser light and output a photoreception signal, the laser light being reflected by an object to be measured that is provided on the first optical path or the second optical path, and a demodulation circuit configured to demodulate, from the photoreception signal, a Doppler signal derived from the object to be measured, based on a reference signal and a modulation signal derived from the optical modulator, wherein Iq/f≤1×10.sup.−7 is satisfied, where an amplitude value of the current applied to the oscillator that is oscillating is Iq [A] and an oscillation frequency of the oscillator is f [Hz].

A laser interferometer that includes a laser light source configured to emit emission light, a light splitter configured to split the emission light into first split light, and second split light incident on an object to be measured, a light modulator disposed on an optical path on which the first split light advances, and configured to modulate the first split light into a reference light having a different frequency from a frequency of the first split light, an optical path length change unit provided between the light splitter and the light modulator, and configured to change a first optical path length, the first optical path length being an optical path length between the light splitter and the light modulator, a photoreceptor configured to receive an interference light of the reference light and an object light generated by reflecting the emission light at the object to be measured, and to output a light reception signal, and a controller configured to control operation of the optical path length change unit in accordance with a second optical path length, the second optical path length being an optical path length between the light splitter and the object to be measured.

A system for a high resolution optical spectrum analyzer (OSA) using various optical configurations to reduce polarization dependent loss (PDL) is disclosed. The system may include a birefringent element to receive an input optical beam. The birefringent element may then split the input optical beam into a first optical beam and a second optical beam. The system may also include an optical configuration, which may determine an optical beam path associated with the first optical beam and the second optical beam, transmit the first optical beam in a first direction along the optical beam path and transmit the second optical beam in a second direction along the optical beam path.

An optical assembly for a laser projection and return laser light detection device comprises a housing; a first series of components arranged in the housing to define an exit path for laser radiation entering from a laser source and then exiting from the housing; a second series of components arranged in the housing to define a return path for scattered returns of the laser radiation entering the housing and passing to a detector; a polarising beam splitter/combiner common to the exit path and the return path arranged to polarise laser light exiting from the housing and to separate scattered laser light returned to the assembly, that is orthogonally polarised to the exiting laser radiation. The polarising beam splitter/combiner forms a window to the housing.