An optical transmitter according to one embodiment includes a housing with an emission end, a light emitting element mounted on a first mounting portion of the housing, and a light receiving element mounted on a second mounting portion of the housing to monitor output light from the light emitting element. The second mounting portion is provided with a carrier, a first resin located on an emission end side of a lower side of the carrier, and a second resin located on a light emitting element side of the lower side of the carrier. A coefficient of thermal expansion of the first resin is smaller than a coefficient of thermal expansion of the second resin.

According to one embodiment, a light source includes a plurality of light-emitting elements each including one or more surface-emitting lasers; and a plurality of detecting elements located on a same substrate as the light-emitting elements. The detecting elements individually detect quantities of output light of the light-emitting elements.

The present disclosure discloses a regulator circuit and regulator system for a tunable laser, the regulator circuit for the tunable laser includes a control module, a digital-to-analog conversion module and a semiconductor temperature regulation module; after the regulator circuit for the tunable laser is powered on, the control module is configured to send a control signal to the digital-to-analog conversion module, the digital-to-analog conversion module is configured to convert the control signal into an analog voltage signal and send the analog voltage signal to the semiconductor temperature regulation module, the semiconductor temperature regulation module is configured to cool or heat the tunable laser according to the received analog voltage signal.

In a laser light emitting device including a plurality of laser light emitter each including a laser diode, a drive circuit configured to drive the laser diode by controlling the supply of a drive current to the laser diode, and a drive line through which the drive current flows from the drive circuit to the laser diode, a light emission detector includes a detection pattern placed so as to cause an electromagnetically induced current to flow in response to a drive current flowing through each drive line when the corresponding laser light emitter emits light. The light emission detector detects light emission from a driven laser diode by detecting the current flowing in the detection pattern.

In a laser light emitting device including a plurality of laser light emitter each including a laser diode, a drive circuit configured to drive the laser diode by controlling the supply of a drive current to the laser diode, and a drive line through which the drive current flows from the drive circuit to the laser diode, a light emission detector includes a detection pattern placed so as to cause an electromagnetically induced current to flow in response to a drive current flowing through each drive line when the corresponding laser light emitter emits light. The light emission detector detects light emission from a driven laser diode by detecting the current flowing in the detection pattern.

A controller stabilizes a distributed feedback plus reflection (DFB+R) laser, which has a back facet, a DFB section, a passive section, and a front facet with a low reflective element. An etalon filter is formed by a portion of the DFB section, the passive section, and the low reflective element. Control circuitry directly modulates the DFB section with a modulation signal and biases the passive section with a bias signal. In operation, a lasing mode of the DFB section is aligned to a long wavelength edge of one of the periodic peaks of a reflection profile of the etalon filter. Meanwhile, photodiodes are arranged to monitor the output power emitted from the laser's front and back facets. The control circuitry monitors a ratio of the detected output power and adjusts the bias based on the monitored ratio.

A controller stabilizes a distributed feedback plus reflection (DFB+R) laser, which has a back facet, a DFB section, a passive section, and a front facet with a low reflective element. An etalon filter is formed by a portion of the DFB section, the passive section, and the low reflective element. Control circuitry directly modulates the DFB section with a modulation signal and biases the passive section with a bias signal. In operation, a lasing mode of the DFB section is aligned to a long wavelength edge of one of the periodic peaks of a reflection profile of the etalon filter. Meanwhile, photodiodes are arranged to monitor the output power emitted from the laser's front and back facets. The control circuitry monitors a ratio of the detected output power and adjusts the bias based on the monitored ratio.

An apparatus includes an optical splitter configured to receive an optical signal and to split the input optical signal to provide a first and a second optical signal. The apparatus further includes an interferometer comprising a first arm and a second arm, with the first arm being configured to receive the first optical signal, and the second arm being configured to receive the second optical signal. Notably a portion of the first arm is exposed to a reference gas that attenuates light of a characteristic wavelength. The apparatus further includes an optical coupler configured to receive an output optical signal from the first arm, and an output optical signal from the second arm and to provide a third optical signal; and a photodetector configured to receive the third optical signal, and to provide a photocurrent. The photocurrent increases when the difference between the characteristic wavelength and the wavelength of the optical signals increases. The apparatus also comprises a feedback control circuit configured to change the properties of the laser to be locked until an error signal indicative of the difference between the characteristic wavelength and the wavelength of the laser is substantially zero.

An apparatus includes an optical splitter configured to receive an optical signal and to split the input optical signal to provide a first and a second optical signal. The apparatus further includes an interferometer comprising a first arm and a second arm, with the first arm being configured to receive the first optical signal, and the second arm being configured to receive the second optical signal. Notably a portion of the first arm is exposed to a reference gas that attenuates light of a characteristic wavelength. The apparatus further includes an optical coupler configured to receive an output optical signal from the first arm, and an output optical signal from the second arm and to provide a third optical signal; and a photodetector configured to receive the third optical signal, and to provide a photocurrent. The photocurrent increases when the difference between the characteristic wavelength and the wavelength of the optical signals increases. The apparatus also comprises a feedback control circuit configured to change the properties of the laser to be locked until an error signal indicative of the difference between the characteristic wavelength and the wavelength of the laser is substantially zero.

A LIDAR transmitter system comprising an array of laser energy sources, each laser energy source comprising a corresponding photodetector. The laser energy sources are configured to emit laser energy towards a LIDAR target. Each respective photodetector is configured to detect the laser energy emitted by a corresponding energy source of the array.