An optoelectronic device includes a base chip, including a silicon die having a photodiode disposed at its front surface and a first anode contact and a first cathode contact disposed on the front surface. A laser diode driver circuit on the silicon die supplies an electrical drive signal between the first anode contact and the first cathode contact. An emitter chip includes a III-V semiconductor die, which is mounted with its front side facing toward the front surface of the silicon die. A second anode contact and a second cathode contact are disposed on the front side of the III-V semiconductor die in electrical communication with the first anode contact and the first cathode contact. A VCSEL is disposed on the front side of the III-V semiconductor die in coaxial alignment with the photodiode and receives the drive signal from the second anode contact and the second cathode contact.

This optical transmission module includes: a plurality of semiconductor lasers provided on a sub-mount fixed to a side surface of a block fixed on a plate-shaped stem made of metal; and a cap with a lens fixed thereto, the cap covering all members placed above the stem. The same number of lead pins as the semiconductor lasers are provided so as to respectively penetrate through a plurality of holes formed in the stem. The lead pins and the semiconductor lasers are electrically connected to each other, respectively. Single-phase electrical signals with the stem as a ground potential are respectively applied to the semiconductor lasers from an external power supply, through the lead pins, respectively, so as to cause modulation and oscillation of the semiconductor lasers.

A laser device includes a laser oscillator configured to emit a laser beam, and an optical unit configured to receive the laser beam and emit the laser beam outside. The optical unit includes: a partially transmissive mirror configured to reflect a part of the laser beam toward the outside and transmit a remaining part of the laser beam; a diffusion plate configured to diffuse the laser beam which has passed through the partially transmissive mirror and deflect the laser beam in a predetermined direction, at a predetermined diffusion angle; and a photodiode configured to receive the laser beam deflected by the diffusion plate, and output an electric signal. The laser device is configured such that deviation of an optical axis of the laser beam is monitored based on the electric signal of the photodiode.

A mirror driving mechanism includes a plate-shaped base portion, a mirror that is installed at the base portion, and a temperature detecting section that is installed at the base portion and that detects a temperature of the base portion. The base portion includes a thin portion that is disposed away from an outer edge of the base portion and that has a through hole extending through the base portion in a plate-thickness direction of the base portion, a thick portion that is connected to the thin portion, that is thicker than the thin portion in the plate-thickness direction of the base portion, and that extends along the outer edge so as to surround the thin portion, and a first shaft portion extends into the through hole from an outer periphery of the through hole.

A light-emitting device includes first and second light-emitting elements, upper submounts, and a lower submount. The upper submounts include a first submount having a first upper surface and a first lateral surface located on a same side as an emission end surface of the first light-emitting element, and a second submount having a second upper surface and a second lateral surface located on a same side as an emission end surface of the second light-emitting element. In a top plan view, the first lateral surface is located forward relative to the second lateral surface, and the emission end surface of the first light-emitting element is located forward relative to the emission end surface of the second light-emitting element. At least a portion of the first lateral surface is protruded forward relative to an edge along which an upper surface and a lateral surface of the lower submount meet.

A laser diode drive system for generating a drive current for a laser diode is described. The laser diode drive system comprises a first laser diode driver connected to the laser diode by a first cable to provide a drive current source for the laser diode. A second laser diode driver is then connected to the laser diode by a second cable to provide a low current sink for the laser diode. A feedback control loop is employed to provide a feedback signal for the second laser diode driver from to sample of an output field of the laser diode. The laser diode drive system exhibits low power consumption while being capable of creating sufficient feedback bandwidth to reduce the excess optical noise by at least an order of magnitude at 1 MHz compared with laser diode drive systems comprising just a first laser diode driver.

A laser processing apparatus includes a semiconductor laser element, a waveform output unit for outputting input waveform data, a driver circuit for supplying a drive current having a time waveform according to the input waveform data to the semiconductor laser element, and a processing optical system for irradiating a processing object with laser light. The semiconductor laser element outputs the laser light in which two or more light pulse groups each including one or a plurality of light pulses are provided with a time interval therebetween. Time waveforms of at least two light pulse are different from each other. The time waveform includes at least one of a time waveform of each of the one or plurality of light pulses, a time width of each of the one or plurality of light pulses, and a time interval of the plurality of light pulses.

A light emitting device includes: a base having a bottom face and a lateral part surrounding the bottom face and extending upwards from the bottom face, wherein the lateral part comprises a first stepped portion and a second stepped portion facing the first stepped portion; a first semiconductor laser element disposed on the bottom face and located between the first stepped portion and the second stepped portion in a top view, wherein the first semiconductor laser element is configured to emit light towards the second stepped portion; a first wiring region located on the first stepped portion; and one or more first wires, each having a first end that is connected to the first wiring region. At least one of the one or more first wires is electrically connected to the first semiconductor laser element.

A system is proposed for continuously monitoring the integrity of a transmission fiber coupled to a laser source and immediately shutting down the laser source upon recognition of any type of cut, break or disconnect along the transmission fiber. A pair of monitoring photodiodes is included with the laser source and used to look at the ratio of reflected light to transmitted light, shutting down the laser if the ratio exceeds a given threshold. If a break is present, the power of the reflected light will be higher than normal, where a defined threshold is used to determine of the calculated intensity is indicative of a break. By using measurements performed in terms of decibels, the monitoring system needs only to take the difference in intensities to generate the reflection/transmission ratio output.

A laser diode drive system configured to output a drive signal to control a voltage provided to a laser diode can include a circuit sensor system configured to output a sensed signal indicative of a drive current of a laser diode, and a temperature sensor configured to output a temperature signal indicative of a temperature of the laser diode or an ambient temperature of the laser diode. The system can include a temperature compensation system configured to output a correction signal based on the temperature signal to compensate for a temperature dependent factor in the sensed signal.