A deterioration diagnosis device includes: a temperature acquisition unit acquiring a temperature of an optical transceiver including a laser diode outputting an optical transmission signal; a bias current acquisition unit acquiring a bias current flowing through the diode; a correction function calculation unit calculating a correction function representing a relationship between the acquired temperature and bias current; a temperature correction value calculation unit calculating a temperature correction value for a bias current acquired at the time of deterioration diagnosis, using the correction function; a corrected bias current calculation unit correcting the bias current acquired at the time of the deterioration diagnosis, using the temperature correction value; and a bias current change amount calculation unit determining a state of the laser diode by comparing an initial bias current with a corrected bias current.

In embodiments, an apparatus to predict failure of a laser is presented. The apparatus may include a memory to store a reference model of bias current change for a laser as a function of time and temperature, one or more sensors to detect: temperature, elapsed operating time and bias current of the laser, and a processor communicatively coupled to the memory and to the one or more sensors. The processor may be to calculate an actual bias current change ΔIA at a current laser temperature, and an expected bias current change ΔIE, based at least in part on the reference model and an average operating temperature, subtract ΔIE from ΔIA, and if the difference is greater than a pre-defined value α, output a signal. Related methods and non-transitory computer-readable media may also be presented.

A laser apparatus comprising a laser diode module/cooling plate assembly in which a plurality of LD modules to which a driving current is supplied in series is disposed on the surface of a cooling plate, comprising: a laser power source; switch valves for switching a flow direction of a cooling liquid flowing through a cooling liquid flow path; a timing determination apparatus for determining the timing for switching the flow direction of the cooling liquid, by referencing temperature time series data of at least any one temperature variation part in the laser diode module/cooling plate assembly having temperature variations due to heat generated in a heat-generating part of the laser diode module; and a control circuit for outputting a driving current output command to the laser power source and outputting a valve switch command to the switch valves by referencing the determination result of the timing determination apparatus.

A multipiece element storage package of the present disclosure includes: a mother substrate which includes first element storage package regions, second element storage package regions, a dummy region, a first surface, and a second surface; a first stem electrode disposed in a part of the dummy region which part is in the first surface; and a second stem electrode disposed on the second surface. The first element storage package regions and the second element storage package regions each include a frame body disposed on the first surface, a first wiring conductor disposed on the first surface, and including one end located inside the frame body and the other end connected to the first stem electrode, and a second wiring conductor including one end which is located on the first surface and inside the frame body and the other end which is connected to the second stem electrode.

An embodiment relates to a surface emitting laser device and a light emitting device including the same. The surface emitting laser device according to the embodiment includes: a first emitter having a first aperture and a first insulating region; a second emitter having a second aperture and a second insulating region and disposed adjacent to the first emitter; a third emitter having a third aperture and a third insulating region and disposed adjacent to the first emitter and the second emitter; and a first trench region disposed between the first emitter and the third emitter. The first trench region is disposed inside a virtual triangle connecting a center of the first aperture of the first emitter, a center of the second aperture of the second emitter, and a center of the third aperture of the third emitter.

A photonic integrated circuit (PIC) includes a semiconductor substrate, one or more passive components, and one or more active components. The one or more passive components are fabricated on the semiconductor substrate, wherein the passive components are fabricated in a III-V type semiconductor layer. The one or more active components are fabricated on top of the one or more passive components, wherein optical signals are communicated between the one or more active components via the one or more passive components.

A heterostructure laser is provided comprising an epitaxially grown substrate of first dopant type, an active region and layer of second dopant type, a narrow mesa having less than 20% open area and a side wall slope of less than 85 degrees, wherein said narrow mesa is etched through the active region and layer of second dopant type using in-situ MOCVD, a plurality of current blocking layers, an overclad layer and a contact layer of second dopant type, and an isolation mesa incorporating the narrow mesa, wherein the isolation mesa is etched through the active region, layer of second dopant type and plurality of current blocking layers and wherein the plurality of current blocking layers is grown without exposure to oxygen.

A semiconductor laser element that includes a semiconductor layer including a waveguide formed in an intra-layer direction of the semiconductor layer and a window region formed in a front-side end face of the waveguide, has a current-laser optical output characteristic in which, at an operating temperature of 25° C.±3° C., a laser optical output has a maximum value at a first driving current value and the laser optical output is at most 20% of the maximum value at a second driving current value greater than the first driving current value, and is not damaged at the second driving current value.

An emitter array, may comprise a first set of emitters that has a nominal optical output power at an operating voltage. The emitter array may comprise a second set of emitters that has substantially less than the nominal optical output power or no optical output power at the operating voltage. The first set of emitters and the second set of emitters may be interleaved with each other to form a two-dimensional regular pattern of emitters that emits a random pattern of light at the nominal optical output power at the operating voltage. The first set of emitters and the second set of emitters may be electrically connected in parallel.

A photonic integrated circuit (PIC) includes a semiconductor substrate, one or more passive components, and one or more active components. The one or more passive components are fabricated on the semiconductor substrate, wherein the passive components are fabricated in a III-V type semiconductor layer. The one or more active components are fabricated on top of the one or more passive components, wherein optical signals are communicated between the one or more active components via the one or more passive components.