A measurement system is provided with an array of laser diodes with one or more Bragg reflectors. At least a portion of the light generated by the array is configured to penetrate tissue comprising skin. A detection system configured to: measure a phase shift, and a time-of-flight, of at least a portion of the light from the array of laser diodes reflected from the tissue relative to the portion of the light generated by the array; generate one or more images of the tissue; detect oxy- or deoxy-hemoglobin in the tissue; non-invasively measure blood in blood vessels within or below a dermis layer within the skin; measure one or more physiological parameters based at least in part on the non-invasively measured blood; and measure a variation in the blood or physiological parameter over a period of time.

Photonic chip includes an external cavity (EC) optical circuit to provide wavelength-selective optical feedback to a length of active optical fiber. Light generated in the active optical fiber may be coupled from the EC circuit to a light processing circuit of the photonic chip, such as an optical modulator or an optical mixer. The EC circuits may include single-frequency and multi-frequency optical filters, which may include ring resonators, dual-ring resonators, and optical modulators to support multi-frequency lasers. The EC circuits may further include pump combiners and optical isolators.

An optical arrangement for adjusting the wavelength of light, comprising: a first light source arranged to generate a first beam of light at a first wavelength; a second light source arranged to generate seed light at a second wavelength; a first Raman shifting medium arranged to receive the light from the first light source in combination with the seed light from the second light source, and to produce, by stimulated Raman scattering, output light at the second wavelength and having temporal properties determined by those of the first beam of light; a third light source arranged to generate seed light at a third wavelength; and a second Raman shifting medium arranged to receive the output light from the first Raman shifting medium in combination with the seed light from the third light source, and to produce, by stimulated Raman scattering, output light at the third wavelength and having temporal properties determined by those of the output light from the first Raman shifting medium; wherein the third wavelength is greater than the second wavelength, and the second wavelength is greater than the first wavelength; wherein the frequency difference between the first beam of light and the seed light from the second light source is a frequency difference where the first Raman shifting medium exhibits Raman gain; and wherein the frequency difference between the output light from the first Raman shifting medium and the seed light from the third light source is a frequency difference where the second Raman shifting medium exhibits Raman gain. Also provided is a corresponding method of adjusting the wavelength of light.

The present invention discloses a grating enhanced distributed vibration demodulation system based on three-pulse shearing interference, comprising: a laser device, a pulse optical modulator, a three-pulse generation polarization-maintaining structure, a first erbium-doped fiber amplifier, a first optical circulator, a fiber grating array, a second erbium-doped fiber amplifier, a second optical circulator, a three-in-three optical coupler, a first Faraday rotator mirror, a second Faraday rotator mirror, and a four-channel data acquisition card, On the basis of a distributed fiber grating vibration sensing system, three-pulse dislocation interference and three-in-three optical coupler digital phase demodulation technologies are adopted, XX and XY pulses are utilized to complement interference visibility, and demodulation is performed by selecting a better path, so that polarization fading resistance and interference signal high visibility in the distributed fiber grating vibration sensing system are realized.

The present disclosure generally relates optical amplifier modules. In one form for example, an optical amplifier module includes a booster optical amplifier configured to increase optical power of a first optical signal. The module also includes a preamp optical amplifier configured to increase optical power of a second optical signal and a pump laser optically coupled to the booster optical amplifier and the preamp optical amplifier. The pump laser is configured to provide a booster power to the booster optical amplifier and a preamp power to the preamp optical amplifier, the preamp power is effective to induce a gain in optical power to provide a target optical power of the second optical signal from the preamp optical amplifier, and the booster power is dependent on the preamp power.

An ultra-compact, high power, fiber pump module apparatus has a heatsink with a stepped outer shape. The heatsink has at least one interior cooling channel. A plurality of single emitter diodes is positioned on one step of the stepped outer shape of the heatsink, respectively. At least two beam-shifting structures are positioned in a beam path of each of the plurality of single emitter diodes. The at least two beam-shifting structures fold each beam emitted from the plurality of single emitter diodes in at least three dimensions. At least one beam combining structure is positioned in the beam path, wherein the at least one beam combining structure combines the beams from each of the plurality of single emitter diodes into a single, combined beam. The single, combined beam is output from the ultra-compact, high power, fiber pump module apparatus.

Systems and methods for optical amplifier failure prediction using Machine Learning (ML), such as for an Erbium-Doped Fiber Amplifier (EDFA), are described. A method include obtaining a plurality of inputs from an optical amplifier associated with an optical network; analyzing the plurality of inputs with a trained machine learning model; obtaining an estimate of a total pump current of the optical amplifier as an output of the trained machine learning model; and comparing the estimate of a total pump current to a measured total pump current of the optical amplifier. The steps can include determining a health of the optical amplifier based on the comparing

An objective of the present invention is to provide an optical amplifier having a cladding excitation configuration that improves amplification efficiency. The optical amplifier includes an optical amplification unit 36 in which n (n is a natural number equal to or greater than 2) amplification fibers 34 that optically amplify signal light propagating through cores with excitation light supplied to claddings and n−1 optical input/output units 35 that input/output the signal light to/from the cores and the outside of the amplification fibers 34 are connected in series such that the amplification fibers 34 and the optical input/output units 35 are disposed in an alternating manner, an excitation light generator 31 that outputs the excitation light in multi-mode, and optical multiplexer/demultiplexers 33 that cause the excitation light from the excitation light generator 31 that has been divided into two light beams to be incident on the claddings of the amplification fibers 34 disposed at both ends of the optical amplification unit 36 and cause the signal light to be input to/output from the cores of the amplification fibers 34 disposed at both ends of the optical amplification unit 36.

A multiple stage optical amplification device in a light detection and ranging (LiDAR) scanning system is provided. The system comprises a first power amplification stage receiving seed laser light and outputting first amplified laser light; a second power amplification stage receiving the first amplified laser light and outputting a second amplified laser light; and a single optical power pump coupled to the second power amplification stage. The second power amplification stage is configured to amplify the first amplified laser light to generate the second amplified laser light. A first portion of pump power provided by the optical power pump is deliverable to the first power amplification stage to amplify the seed laser light.

A Raman amplifier includes a first light source that outputs a primary pumping light, which propagates in a same direction as a propagation direction of a signal light, to an optical transmission line for Raman amplification, a second light source that outputs a secondary pumping light, which pumps and amplifies the primary pumping light and propagates in the same direction as the propagation direction, to the optical transmission line, and a control unit that controls a gain for the signal light by adjusting power of the secondary pumping light.