A chip scale ultra violet laser source includes a plurality of laser elements on a substrate each including a back cavity mirror, a tapered gain medium, an outcoupler, a nonlinear crystal coupled to the outcoupler with a front facet that has a first coating that is anti-reflectivity (AR) to a fundamental wavelength of the laser element and high reflectivity (HR) to ultra violet wavelengths, and has an exit facet that has a second coating that has HR to a fundamental wavelength of the laser element and AR to the ultra violet wavelengths, a photodetector coupled to the outcoupler, a phase modulator coupled to the photodetector and coupled to the back cavity mirror, and a master laser diode on the substrate coupled to the phase modulator of each laser element. Each laser element emits an ultra violet beamlet and is frequency and phase locked to the master laser diode.

A photonic interface for an electronic circuit is disclosed. The photonic interface includes a photonic integrated circuit having a modulator and a photodetector, and an optical fiber or fibers for optical communication with another optical circuit. A modulator driver chip may be mounted directly on the photonic integrated circuit. The optical fibers may be placed in v-grooves of a fiber support, which may include at least one lithographically defined alignment feature for optical alignment to the silicon photonic circuit.

An FM LIDAR system is described that includes a frequency modulated LIDAR system that incorporates a laser source that is optically coupled to a whispering gallery mode optical resonator. Light from the laser that is coupled into the whispering gallery mode optical resonator is coupled back out as a returning counterpropagating wave having a frequency characteristic of a whispering gallery mode of the optical resonator. This returning wave is used to reduce the linewidth of the source laser by optical injection. Modulation of the optical properties of the whispering gallery mode optical resonator results in modulation of the frequency of the frequencies supported by whispering gallery modes of the resonator, and provides a method for producing highly linear and reproducible optical chirps that are highly suited for use in a LIDAR system. Methods of using such an FM LIDAR system and vehicle assisting systems that incorporate such FM LIDAR systems are also described.

This semiconductor laser device includes a semiconductor laser chip and a spatial light modulator SLM which is optically connected to the semiconductor laser chip. The semiconductor laser chip LDC includes an active layer 4, a pair of cladding layers 2 and 7 sandwiching the active layer 4, and a diffraction grating layer 6 which is optically connected to the active layer 4. The spatial light modulator SLM includes a common electrode 25, a plurality of pixel electrodes 21, and a liquid crystal layer LC arranged between the common electrode 25 and the pixel electrodes 21. A laser beam output in a thickness direction of the diffraction grating layer 6 is modulated and reflected by the spatial light modulator SLM and is output to the outside.

A laser interferometer includes a light source that emits first laser light, an optical modulator that includes a vibrator and modulates the first laser light by using the vibrator to generate second laser light including a modulated signal, a photodetector that receives interference light between third laser light including a sample signal generated by reflecting the first laser light on an object and the second laser light to output a light reception signal, a demodulation circuit that demodulates the sample signal from the light reception signal based on a reference signal, and a signal generator that outputs the reference signal input to the demodulation circuit and outputs a drive signal input to the optical modulator, in which Vd/Vr<10, where Vr is a voltage of the reference signal and Vd is a voltage of the drive signal.

The present invention provides a photonic integrated circuit, system, apparatus and method which can be used as an optical transmitter in a system, for example in a telecommunication system. According to the various embodiments of the invention, the circuit includes several optical devices, wherein some are passive and others have gain, which constructed and connected with the specific characteristics, leads to a multi-wavelength transmitter with tunable operation band.

A tunable laser includes a semiconductor optical amplifier (SOA) having a reflective end coupled to a shared reflector and an output end, which is coupled to a demultiplexer through an input waveguide. The demultiplexer comprises a set of Mach-Zehnder (MZ) lattice filters, which function as symmetric de-interleaving wavelength splitters, that are cascaded to form a binary tree that connects an input port, which carries multiple wavelength bands, to N wavelength-specific output ports that are coupled to a set of N reflectors. A set of variable optical attenuators (VOAs) is coupled to outputs of the MZ lattice filters in the binary tree, and is controllable to selectively add loss to the outputs, so that only a single favored wavelength band, which is associated with a favored reflector in the set of N reflectors, lases at any given time. An output waveguide is optically coupled to the lasing cavity.

A Brillouin backscattered spectrum is obtained in such a way that two optical pulse pairs each composed of two pulses of different durations and of the same phase and n phase difference are launched into a sensing optical fiber; Brillouin backscattered lights produced by the optical pulse pairs are detected into signals for the respective optical pulse pairs; the signals are sampled with two window functions whose time widths are equal to respective pulse durations of the optical pulse pair and whose delay time is variable; each sampled signal is transformed with a predetermined transformation; products of the transformed signals are calculated; and subtraction between the products is performed.

A second optical modulator is provided between a semiconductor laser and a first optical modulator. Further, a second optical waveguide branched from a first optical waveguide is provided between the semiconductor laser and the second optical modulator, and a light receiving element which converts received laser light into a second electrical signal is provided at an end of the second optical waveguide. Furthermore, the second optical modulator adjusts a light intensity of the laser light entering the first optical modulator to a fixed light intensity, based on data transmitted as the second electrical signal. Still further, the first optical modulator modulates the laser light based on data transmitted as a first electrical signal, and converts the first electrical signal into an optical signal.

In a multiple-wavelength laser source, a multiple-mode laser outputs a set of wavelengths in a range of wavelengths onto an optical waveguide, where a spacing between adjacent wavelengths in the set of wavelengths is smaller than a width of channels in an optical link. Furthermore, a set of ring-resonator filters in the multiple-wavelength laser source, which are optically coupled to the optical waveguide, output corresponding subsets of the set of wavelengths for use in the optical link based on free spectral ranges and quality factors of the set of ring-resonator filters. These subsets may include one or more groups of wavelengths, with another spacing between adjacent groups of wavelengths that is larger than the width of the given channel in the optical link. In addition, the one or more groups of wavelengths may include one or more wavelengths, with the spacing between adjacent wavelengths in the given group of wavelengths.