A quantum cascade laser includes a semiconductor substrate, an optical waveguide formed on a first surface of the semiconductor substrate, and a temperature adjusting member. The optical waveguide includes a first region and a second region located on one side with respect to the first region in the optical waveguide direction of the optical waveguide. The first region generates a first light having a first wavelength, and the second region generates a second light having a second wavelength. The optical waveguide generates an output light having a frequency corresponding to a difference between the first wavelength and the second wavelength by difference-frequency generation. A recess for suppressing heat transfer between the first region and the second region is formed at a second surface of the semiconductor substrate. The temperature adjusting member includes a first temperature adjusting member for adjusting the temperature of the second region.

A beam combining device and method for a Bragg grating external-cavity laser module has a plurality of side by side light-emitting modules that use a Bragg grating to perform wavelength locking. Output light of the modules is incident to a beam combining element after passing through a focusing optical element for beam combining, and light subjected to beam combining is reflected partially and transmitted partially under the effect of a light splitting element. A part is incident into a dispersion element at a diffraction angle of the element. Parallel light is formed under the effect of a conversion optical element. Spots of the light beams of corresponding wavelengths of the light-emitting modules are formed on an image acquisition mechanism. Whether the wavelengths of the corresponding light-emitting modules are locked is determined by whether there is a deviation between preset spots and spots formed by the module on the acquisition mechanism.

An optical transmitter (201) comprising: a laser diode (102) for transmitting an optical signal; a first temperature sensor (106) configured to measure a temperature at or proximate to the laser diode (102); a second temperature sensor (202) configured to measure a temperature of an environment in which the optical transmitter (201) is operating; a thermoelectric device (208) configured to apply heating or cooling to the laser diode (102); and a controller (212) configured to, using the temperature measurements taken by the first temperature sensor (106) and the second temperature sensor (202), control the thermoelectric device (208) to heat or cool the laser diode (102).

A laser resonator includes an active material, which amplifies light associated with an optical gain of the resonator, and passive materials disposed in proximity with the active material. The resonator oscillates over one or more optical modes, each of which corresponds to a particular spatial energy distribution and resonant frequency. Based on a characteristic of the passive materials, for the particular spatial energy distribution corresponding to at least one of the optical modes, a preponderant portion of optical energy is distributed apart from the active material. The passive materials may include a low loss material, which stores the preponderant optical energy portion distributed apart from the active material, and a buffer material disposed between the low loss material and the active material, which controls a ratio of the optical energy stored in the low loss material to a portion of the optical energy in the active material.

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.

A parallel cavity tunable laser generally includes a semiconductor laser body defining a plurality of parallel laser cavities with a common output. Each of the parallel laser cavities is configured to be driven independently to generate laser light at a wavelength within a different respective wavelength range. The wavelength of the light generated in each of the laser cavities may be tuned, in response to a temperature change, to a channel wavelength within the respective wavelength range. The laser light generated in each selected one of the laser cavities is emitted from the common output at a front facet of the laser body. By selectively generating light in one or more of the laser cavities, one or more channel wavelengths may be selected for lasing and transmission.

An apparatus and method of assembly are described that provide improved mechanisms for cooling an optoelectronic transducer in a fiber optic system. The apparatus includes a thermoelectric cooler (TEC) secured to the optoelectronic transducer for removing heat from the optoelectronic transducer in response to instructions from a TEC driver, as well as a microcontroller electrically connected to the TEC driver for monitoring temperature and communicating with the TEC driver to selectively activate and deactivate the TEC at least partially based on the monitored temperature and/or other measured/detected data to effect a more efficient cooling mechanism for optoelectronic transducers, such as VCSELs. In addition, the user may be able to configure the system to maintain the optoelectronic transducer within a user-defined range of temperatures. In this way, a longer life and better performance of the optoelectronic transducer may be achieved, and datacenter costs related to cooling and/or maintenance may be minimized.

A laser radar system includes a first light source unit including a signal light source —a seed laser diode or a light source for amplifying a laser beam from the seed laser diode —and a pump laser diode, a second light source unit disposed to be spaced apart from the first light source unit, the second light source unit including an optical amplifier for amplifying a signal output from the first light source unit, and an optical connector for connecting the first light source unit and the second light source unit to each other, wherein the second light source unit is disposed at an end of a laser transceiver unit of the laser radar system.

A two-section semiconductor laser includes a gain section and a modulation-independent grating section to reduce chirp. The modulation-independent grating section includes a diffraction grating for reflecting light and forms a laser cavity with the gain section for lasing at a wavelength or range of wavelengths reflected by the diffraction grating. The gain section of the semiconductor laser includes a gain electrode for driving the gain section with at least a modulated RF signal and the grating section includes a grating electrode for driving the grating section with a DC bias current independent of the modulation of the gain section. The semiconductor laser may thus be directly modulated with the modulated RF signal without the modulation significantly affecting the index of refraction in the diffraction grating, thereby reducing chirp.

A header, with improved cooling for electronic components for radio frequency signal transmission, for an electronic component for radio frequency data transfer, includes: a metallic base body including a plurality of electrical feedthroughs; a thermoelectric cooling element having one side bearing on the base body and an opposite side for mounting the electronic component; a radio frequency line to the electronic component being on the side for mounting the electronic component, with a ground conductor that is electrically connected to the metallic base body, the electrical connection to the metallic base body including a telluride element.