A time-of-flight (ToF) transmitter with self-stabilized optical output phase with minimal overhead is described, where the transmitter may either function as a slave in that the laser pulse phase and width can be controlled by the master ToF receiver, or it can function as a master where the laser control pulse is generated on the same chip or a companion chip. When the ToF transmitter functions as a slave and receives the laser pulse control signal, the techniques of this disclosure can transform the receive path and the pre-driver circuit into part of a delay locked loop (DLL).

The present embodiment relates to a light-emitting device that enables reduction in attenuation or diffraction effect caused by a semiconductor light-emitting device with respect to modulated light outputted from a spatial light modulator, and the light-emitting device includes the semiconductor light-emitting device that outputs light from a light output surface and the reflection type spatial light modulator that modulates the light. The spatial light modulator includes a light input/output surface having the area larger than the area of a light input surface of the semiconductor light-emitting device, modulates light taken through a region facing the light output surface of the semiconductor light-emitting device in the light input/output surface, and outputs the modulated light from another region of the light input/output surface to a space other than the light input surface of the semiconductor light-emitting device.

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 technique related to a semiconductor chip is provided. An optical gain chip is attached to a semiconductor substrate. An integrated photonic circuit is on the semiconductor substrate, and the optical gain chip is optically coupled to the integrated photonic circuit thereby forming a laser cavity. The integrated photonic circuit includes an active intra-cavity thermo-optic optical phase tuner element, an intra-cavity optical band-pass filter, and an output coupler band-reflect optical grating filter with passive phase compensation. The active intra-cavity thermo-optic optical phase tuner element, the intra-cavity optical band-pass filter, and the output coupler band-reflect optical grating filter with passive phase compensation are optically coupled together.

A tunable laser includes a reflective silicon optical amplifier (RSOA) with a reflective end and an interface end and an array of narrow-band reflectors, which each have a different center wavelength. It also includes a silicon-photonic optical switch, having an input port and N output ports that are coupled to a different narrow-band reflector in the array of narrow-band reflectors. The tunable laser also includes an optical waveguide coupled between the interface end of the RSOA and the input of the silicon-photonic optical switch. The frequency of this tunable laser can be tuned in discrete increments by selectively coupling the input port of the silicon-photonic optical switch to one of the N output ports, thereby causing the RSOA to form a lasing cavity with a selected narrow-band reflector coupled to the selected output port. The tunable laser also includes a laser output optically coupled to the lasing cavity.

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.

Methods, systems, and apparatus, for optical communication. One apparatus includes a Fabry-Perot (FP) laser diode assembly coupled to a first port of a circulator; an optical amplifier coupled to a second port of the circulator; a wavelength division multiplexer (WDM) filter coupled to a third port of the circulator; and a Faraday rotator mirror coupled to the WDM filter.

An object of the present invention is to reduce errors caused by changes in delay time when driving a light-emitting element. A light-emission driving device (10) includes: a light-emission current detection unit (401) (12); a phase difference detection unit (300); and a delay unit (200). The light-emission current detection unit (401) (12) detects a light-emission current for causing a light-emitting element (20) to emit light, the light-emission current being supplied from a light-emission driving unit (110). The phase difference detection unit (300) detects a phase difference between the detected light-emission current and a drive signal for controlling the supply of the light-emission current in the light-emission driving unit (110). The delay unit (200) adjusts propagation delay of the drive signal in accordance with the detected phase difference, and supplies the adjusted drive signal to the light-emission driving unit (110) as a drive signal. The present invention can be applied to a light-emitting device of a camera, for example.

Aspects of the present disclosure describe systems, methods and structures including an integrated-optics-based externa-cavity laser configured for mode-hop-free wavelength tuning having an increased continuous tuning range with an ultra-narrow linewidth by increasing tuning sensitivity. Ultra-narrow linewidth is provided by extending cavity length with a multi-pass resonator based filter that may advantageously include tunable microring resonators that enable single-mode oscillation while contributing to the optical length of the laser with multiple passes of light through the ring(s) per roundtrip in the laser cavity. Further aspects of the present disclosure describe systems, methods, and structures exhibiting an enhanced “tuning sensitivity”—defined by a continuous wavelength shift per induced cavity phase shift by a phase section. Such tuning sensitivity is increased by approximately a factor of 3 for synchronous tuning of phase section and ring resonators as compared to tuning phase section only.

To achieve wavelength stabilization in pulsed lasers, a laser oscillator and a laser amplifier are driven with currents in a pre-lasing stage and a lasing stage. The laser oscillator is co-packaged with the laser amplifier.