A laser device includes: a light source including laser diodes; a processor that holds: a maximum current value of a driving current applied to the laser diodes, and a maximum power value of a power of light emitted from the light source; and a memory, coupled to the processor, that stores a relationship between a magnitude of the driving current, a magnitude of the power of the light, and a degree of deterioration of the light source. The processor further refers to the memory and estimates the degree of deterioration from the maximum current value and the maximum power value.

Edge-emitting laser diodes having mirror facets include passivation coatings that are conditioned using an ex-situ process to condition the insulating material used to form the passivation layer. An external energy source (laser, flash lamp, e-beam) is utilized to irradiate the material at a given dosage and for a period of time sufficient to condition the complete thickness of passivation layer. This ex-situ laser treatment is applied to the layers covering both facets of the laser diode (which may comprise both the passivation layers and the coating layers) to stabilize the entire facet overlay. Importantly, the ex-situ process can be performed while the devices are still in bar form.

A laser module includes a base, a carrier mounted on the base, a laser diode mounted on the carrier, an organic adhesive layer provided between the laser diode and the carrier, the organic adhesive layer having an exposed portion exposed between the laser diode and the carrier, a cap fixed to the base, the cap covering the carrier, the laser diode, and the organic adhesive layer, and a cover material covering at least a part of the exposed portion of the organic adhesive layer.

Systems and methods for a system-level Erbium-Doped Fiber Amplifier (EDFA) optical amplifier efficiency metric. The efficiency metric is a single metric that summarizes optical amplifier behavior and has a predictable behavior over various different optical amplifier settings. Specifically, the efficiency metric is simple and elegant. The simplicity is based on the fact the efficiency metric is determined from available data in an optical amplifier, not requiring external monitoring equipment, dithering, etc. The elegance is based on the fact the efficiency metric covers different optical amplifier settings, multiple pumps, etc. and is shown to reflect degradation with these differences in real-world systems accurately. Specifically, the efficiency metric is designed to reflect health in a multiple pump optical amplifier, providing a single value that represents the total pump currents across all of the multiple pumps.

Provided is a laser device including a lower reflective layer, a laser cavity comprising an active layer disposed on the lower reflective layer, an upper reflective layer disposed on the laser cavity, and a blocking structure disposed between the laser cavity and the upper reflective layer, in which the blocking structure includes a first intermediate layer disposed on the laser cavity, a blocking layer disposed on the first intermediate layer and including a through-hole, and a second intermediate layer disposed on the blocking layer.

[Object] To provide a light source device and imaging system capable of issuing a warning to a user in accordance with an actual deterioration state of a light source. [Solution] The light source device includes: at least one light source; a light monitor unit that detects emitted light emitted from the light source; a light source drive unit that controls a drive current or an applied voltage of the light source such that a detection value detected by the light monitor unit indicates a predetermined target value; and a warning unit that performs a primary warning when the drive current or the applied voltage of the light source reaches a predetermined reference value, and performs a predetermined process on a basis of a deterioration level of the light source after the primary warning is performed.

A laser module includes: a laser device that emits a laser beam including a major polarization component and a minor polarization component; a beam splitter that splits the laser beam into the major polarization component and the minor polarization component and that directs the major polarization component and the minor polarization component in different directions; an optical fiber that is optically coupled to the major polarization component split by the beam splitter and externally outputs the major polarization component; a package housing that houses the laser device and that has an inner surface including a minor polarization component irradiation portion that is irradiated by the minor polarization component split by the beam splitter; and a temperature measurement element that is attached to the package housing and that detects a temperature change of the minor polarization component irradiation portion.

A laser device includes a laser diode configured to emit radiation, an output power of the radiation being dependent on a laser diode driving current, and a photodiode configured to receive the radiation emitted by the laser diode. A photodiode current induced in the photodiode by the received radiation is dependent on a power of the received radiation. The laser device further includes circuitry configured to measure the photodiode current for a laser diode driving current and calculate a laser threshold current of the laser diode from the measured photodiode current as a measure of an actual laser threshold current of the laser diode. The circuitry is further configured to detect a malfunction or degradation of the laser diode.

An embodiment provides a beam projector module that includes: a light source configured to output light; a substrate configured to support the light source; an optical device configured to reduce the light in terms of intensity output to a predetermined space; a frame configured to space the optical device apart from the light source by a predetermined distance, the frame forming a closed space with the substrate and the optical device; a temperature sensor configured to measure a temperature of the frame; and a processor configured to control an output of the light source. The processor is configured to operate the light source in an eye-safety mode when a temperature drop rate of the frame exceeds a reference value.

[Problem] To reduce a filter penalty caused by narrowing of an optical signal band due to optical filters having a multiplexing/demultiplexing function in an optical transmission line between transponder units.

[Solution] In an optical transmission system 10A, transponder units 21a to 21n and 22a to 22n connected by optical fibers 14 in which optical filters having a multiplexing/demultiplexing function of an optical signal are interposed include a transmission unit 22 that transmits the optical signal obtained by modulating laser light from a laser light source 34 with an electric signal from a communication apparatus to the optical fibers 14, and a reception unit 23 that receives the optical signal from the optical fibers 14 and converts the received optical signal into an electric signal. The reception unit 23 includes a BER measurement unit that measures a BER, based on a received signal, and feeds the measured BER back to a transmitting side. The transmission unit 22 includes a frequency shift control unit that performs frequency shift control of making a center frequency of the laser light match a center frequency of the received optical signal so that the fed back BER is minimized.