An optical semiconductor device includes an active layer having a plurality of quantum dot layers. The plurality of quantum dot layers include: a first quantum dot layer doped with a p-type impurity; and a second quantum dot layer doped with an n-type impurity and having an emission wavelength different from that of the first quantum dot layer.

An optical system comprising an optoelectronic device having a facet and a coating on the facet. The facet is configured to be in optical communication with at least a first optical medium during a first time period and a second optical medium during a second time period. The first optical medium has a first refractive index and the second optical medium has a second refractive index different from the first refractive index. The coating is configured to provide a first reflectance during the first time period for optical signals in a predetermined wavelength range and to provide a second reflectance during the second time period for optical signals in the predetermined wavelength range wherein the second reflectance is equal to the first reflectance within a negligible margin for optical signals having at least one wavelength in the predetermined wavelength range.

A semiconductor laser includes a horizontal laser element including a first semiconductor layer arrangement having a first active zone for generating radiation. The horizontal laser element furthermore includes a first optical resonator extending in a direction parallel to a first main surface of the first semiconductor layer arrangement. Lateral boundaries of the first semiconductor layer arrangement run obliquely, such that electromagnetic radiation generated is reflectable in a direction of the first main surface of the first semiconductor layer arrangement. The semiconductor laser furthermore includes a vertical laser element having a second optical resonator extending in a direction perpendicular to the first main surface of the first semiconductor layer arrangement. The vertical laser element is arranged above the first semiconductor layer arrangement on the side of the first main surface in a beam path of electromagnetic radiation reflected at one of the lateral boundaries of the first semiconductor layer arrangement (112).

A light source includes: a seed light source configured to output incoherent seed light with a predetermined bandwidth; and a booster amplifier that is a semiconductor optical amplifier configured to optically amplify the seed light input from a first facet, and output the amplified seed light as amplified light from a second facet, wherein the first facet and the second facet of the booster amplifier are subjected to a reflection reduction treatment, the booster amplifier is configured to operate in a gain saturated state, and relative intensity noise (RIN) and ripple are simultaneously suppressed in the amplified light.

A light source includes: a seed light source configured to output incoherent seed light with a predetermined bandwidth; and a booster amplifier that is a semiconductor optical amplifier configured to optically amplify the seed light input from a first facet, and output the amplified seed light as amplified light from a second facet, wherein the first facet and the second facet of the booster amplifier are subjected to a reflection reduction treatment, the booster amplifier is configured to operate in a gain saturated state, and relative intensity noise (RIN) and ripple are simultaneously suppressed in the amplified light.

The present disclosure discloses a miniaturized MOPA structure DPSSL (Diode Pumped Solid State Laser), which comprises a laser oscillator module and a laser amplifier module. The laser oscillator module consists of a seed laser and its collimating system, and the laser amplifier module consists of a laser pump module and a laser gain element. The seed laser with high beam quality is collimated by collimation system, then input into the gain element; the pump laser is pumped into the gain element via end pump or side pump mode. The seed laser beam transmits into the gain medium and is reflected by the interface several times with the “Zigzag” path, which makes the seed laser fully gained and amplified, finally achieving high power and high beam quality laser output.

In this present disclosure, the laser gain material is doped with different rare-earth ion concentrations and processed into different shapes. Some polishing surfaces of the gain material are deposited with different coatings including HR coating and AR coating, on the one hand, to improve the absorption efficiency of the pump laser, on the other hand, to make the seeds laser in the gain element achieve longer transmission distance by Zigzag transmission path, so that the energy in the gain medium can be fully extracted. And finally, achieve high power laser output.

The present disclosure can adopt the host material doped at least at the same time with Er and Yb elements as the laser gain medium, adopt high-quality 1.55-micron or other medium emission peak band seed laser source as well as end or side pump mode, and can realize the laser output with high power and high beam quality.

Compared with the MOPA laser of the prior art, the present disclosure has the advantages of simple structure, small volume, and low cost.

An optical device includes an optical coupler that inputs an optical signal received from a light source, a semiconductor optical amplifier that amplifies the optical signal received from the optical coupler, and a light receiving element that receives spontaneous emission light received from the semiconductor optical amplifier. The optical coupler includes a first input port to which the optical signal received from the light source is input, a second input port that is connected to an input stage of the light receiving element and that is different from the first input, and an output port that is connected to an input stage of the semiconductor optical amplifier, and that outputs optical signal received from the first input port to the semiconductor optical amplifier. The light receiving element receives, via the output port and the second input port, spontaneous emission light received from the semiconductor optical amplifier.

Provided is an optical isolator including a semiconductor substrate, an optical attenuator and an optical amplifier aligned with each other on the semiconductor substrate, an input optical waveguide connected to the optical attenuator, and an output optical waveguide connected to the optical amplifier, wherein a gain of the optical amplifier decreases based on an intensity of light incident on the optical amplifier increasing, wherein a first input light incident on the optical attenuator through the input optical waveguide is output as a first output light through the output optical waveguide, and a second input light incident on the optical amplifier through the output optical waveguide is output as a second output light through the input optical waveguide, and wherein when an intensity of the first input light and an intensity of the second input light are equal, an intensity of the first output light is greater than an intensity of the second output light.

Embodiments of the present disclosure include optical transmitters and transceivers with improved reliability. In some embodiments, the optical transmitters are used in network devices, such as in conjunction with a network switch. In one embodiment, lasers are operated at low power to improve reliability and power consumption. The output of the laser may be modulated by a non-direct modulator and received by integrated optical components, such as a modulator and/or multiplexer. The output of the optical components may be amplified by a semiconductor optical amplifier (SOA). Various advantageous configurations of lasers, optical components, and SOAs are disclosed. In some embodiments, SOAs are configured as part of a pluggable optical communication module, for example.

Embodiments of the present disclosure include optical transmitters and transceivers with improved reliability. In some embodiments, the optical transmitters are used in network devices, such as in conjunction with a network switch. In one embodiment, lasers are operated at low power to improve reliability and power consumption. The output of the laser may be modulated by a non-direct modulator and received by integrated optical components, such as a modulator and/or multiplexer. The output of the optical components may be amplified by a semiconductor optical amplifier (SOA). Various advantageous configurations of lasers, optical components, and SOAs are disclosed. In some embodiments, SOAs are configured as part of a pluggable optical communication module, for example.