Noise in cavity enhanced spectroscopy due to higher order mode excitation in a resonant cavity is reduced. There are two main points. The first point is that the source and detector are both fiber coupled, to provide the spatial filtering and other general advantages of fiber coupling. The second point is that the cavity is designed to ensure sufficient separation in frequency between the desired TEM.sub.00 mode and the first few higher order spatial modes.

A microscope for examining a specimen configured to receive a first light source or a second light source. The first light source being configured to emit a first output light through a first pupil, and the second light source being configured to emit a second output light through a second pupil that is different than the first pupil. The microscope comprises a frame, a source objective, and first and second optical assemblies. The first and second optical assemblies are removably connectable to the frame. The first optical assembly comprises a first set of optical elements that are configured to pass the first output light to an imaging pupil of the source objective, and the second optical assembly comprises a second set of optical elements configured to pass the second output light to the imaging pupil.

A photo-thermal speckle spectroscopy device having an infrared laser, a visible laser, a foam, and a camera. The infrared and visible lasers are focused on the foam, which causes the visible laser to scatter. A camera records the speckle pattern, which shifts when the IR laser is turned on. The related method of photo-thermal speckle spectroscopy is also disclosed.

A spectral analysis device is provided herein. The spectral analysis device includes a first lens, a transmission grating, a lens set and a sensing element. The first lens is configured to receive and converge an incident light beam into a first light beam. The transmission grating is configured to disperse the first light beam into a plurality of second light beams. The lens set is configured to receive the plurality of second light beams. The sensing element includes a substrate and a plurality of pixels. The plurality of pixels is configured to respectively receive the plurality of second light beam. Such structure is used to analyze the spectrum of incident light.

A Brillouin modality can be supplemented by an auxiliary modality, such as an optical imaging modality or a spectroscopy modality. In some embodiments, the auxiliary modality can be used to guide the Brillouin measurement to a desired region of interest, so that acquisition times for the Brillouin measurement can be reduced as compared to interrogating the entire sample. The auxiliary modality may have an acquisition speed faster than that of the Brillouin modality. In some embodiment, the auxiliary modality determines a composition of materials within a voxel in the sample interrogated by the Brillouin modality. Using the information provided by the auxiliary modality, the Brillouin signatures corresponding to the materials within the voxel can be unmixed, thereby providing a more accurate measurement of the sample.

An example system can include a support and two or more sensor elements mounted to the support. Each sensor element can be electrically connected to a common electrical node and may include: a respective quench resistor connected to a respective internal node; and a respective photodiode (PD) connected to the respective internal node; a differentiating element fed by at least one of the photodiodes; a first readout electrode fed by the common electrical node; and a second readout electrode fed by the differentiating element. The common electrical node may be connected to at least one of the quench resistors or at least one of the photodiodes.

Described herein are optical sensing devices for photonic integrated circuits (PICs). A PIC may comprise a plurality of waveguides formed in a silicon on insulator (SOI) substrate, and a plurality of heterogeneous lasers, each laser formed from a silicon material of the SOI substrate and to emit an output wavelength comprising an infrared wavelength. Each of these lasers may comprise a resonant cavity included in one of the plurality of waveguides, and a gain material comprising a non-silicon material and adiabatically coupled to the respective waveguide. A light directing element may direct outputs of the plurality of heterogeneous lasers from the PIC towards an object, and one or more detectors may detect light from the plurality of heterogeneous lasers reflected from or transmitted through the object.

A printer incorporating a spectrometry device includes a spectroscope that includes a light receiving optical system including a light receiver which receives reflected light from a range of measurement in a medium, a distance sensor that detects the distance between the medium and the spectroscope, and a reflecting mirror driver and an optical path adjuster that adjust the optical path of the reflected light which is incident on the light receiving optical system from the range of measurement according to the distance detected by the distance sensor.

Apparatus for determining information associated with reflection characteristics of a surface comprising a sensor (60) configured to generate sensor output dependent on an intensity of light incident on the sensor and having a field of view directed at an external surface (57) in use; an illumination source (58) configured to emit light onto the external surface in use; an optically transparent window (61) located such as to allow light to pass from the illumination source to the external surface and to allow light to pass to the sensor from the external surface in use; a light concentrator (66) fixed to or integral with the window, the light concentrator being configured to concentrate at least some light from the illumination source onto the external surface in use such that the concentrated light may be reflected from the external surface onto the sensor via the window; and a processor (40) configured to use the sensor output to determine information associated with reflection characteristics of the external surface.

A method for phase contrasting-correlation spectroscopy: converting an incident linearly polarized light into two polarized components (polarized divergent and convergent components, wherein the polarized divergent component is orthogonal to the polarized convergent component), focusing each of the polarized divergent component and the polarized convergent component into a focal plane, thereby producing two focus planes constituting a reference focus (RF) plane and a sample focus (SF) plane; placing a sample at the SF plane and ambient conditions of the sample at the RF plane, resulting in a phase shift between the two polarized components; reconstituting the two phase-shifted polarized components into a phase-shifted linearly polarized light; detecting the phase-shifted linearly polarized light; calculating phase and intensity of the sample from the phase-shifted linearly polarized light; establishing an autocorrelation of phase and intensity of the phase-shifted linearly polarized light; and generating correlograms of intensity and phase of the phase-shifted linearly polarized light.