[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.

The embodiment relates to a surface emitting laser package and a light emitting device including the same.

The surface-emitting laser package according to the embodiment may include a housing including a cavity, a surface-emitting laser device disposed in the cavity, and a diffusion unit disposed on the housing. The diffusion unit may include a polymer layer and a glass layer disposed on the polymer layer. The polymer layer may include a first polymer layer vertically overlapping the surface emitting laser device, and a second polymer layer not vertically overlapping the surface emitting laser device. The thickness of the first polymer layer may be thinner than the thickness of the second polymer layer.

Example embodiments disclose a tunable optical pair source (TOPS) configured to generate first and second output optical beams having respective first and second frequencies that are phase locked with each other. The TOPS may include a first laser, such as a tunable laser, configured to generate a first laser beam, a radio frequency (RF) oscillator configured to transmit an RF reference signal, a beam splitter in optical communication with the first laser, and an electro-optic modulator configured to modulate the second split beam with the RF reference signal to form a modulated beam having a first sideband comb comprising a plurality of harmonics. Additionally, the TOPS may include an optical filter configured to receive the modulated beam and output a filtered optical beam, and a second laser configured to generate a second laser beam at the second frequency, the second laser being configured to receive the filtered optical beam as a seed.

An ambient light rejecting screen used in a laser light source projector, which generates a light with a first wavelength and a light with a second wavelength, is provided. The screen includes a base, a light absorbing layer, a first filter layer and a second filter layer. The light absorbing layer is disposed on the base. The first filter layer is disposed on the light absorbing layer. The crystallization characteristic of the first filter layer corresponds to the light with the first wavelength and generates a reflective light with the first wavelength, and allows the light with remaining wavelengths to pass through. The second filter layer is disposed on the light absorbing layer. The crystallization characteristic of the second filter layer corresponds to the light with the second wavelength used to generate the reflective light with the second wavelength and allows the light with remaining wavelengths to pass through.

A method and system for using a wavelength tunable semiconductor laser as an excitation source of a fiber optics sensing system (FOSS) based on a thermoelectric control of a laser sweep. A device can include an optical fiber; a set of fiber Bragg gratings disposed within the optical fiber; a single-frequency laser (SFL) operatively connected to the optical fiber; a thermoelectric cooler operatively connected to the SFL; a controller comprising a processor in communication with the thermoelectric cooler; and a nontransitory, computer-readable storage medium in communication with the processor. The nontransitory, computer-readable storage medium can store instructions that, when executed by the processor, cause the processor to perform operations including determining a strain value at a first fiber Bragg grating of the set of fiber Bragg gratings based on a second laser signal received at the device that is reflected from an interaction of a first laser signal with the first fiber Bragg grating.

A multimode laser that generates laser emissions that are transmitted into an optical coupling then an optical filter to test for failures or faults within that optical filter is provided herein. Multimode lasers generate emissions which many different modes are present in the gain curve. Due to this, typical multi-mode laser failure-cases can be observed in the output frequency signal of laser emissions passing through an optical component. By using a spectrometer to analyze the exiting laser wavelengths, specific failure-cases of the optical component can be identified and related to root causes.

A semiconductor-laser-chip-on-submount includes: a semiconductor laser chip that includes a semiconductor portion having an emitting facet and a rear facet along a longitudinal direction and emits laser light from the emitting facet; and a submount where the semiconductor laser chip is mounted. Further, a first distance between the submount and the emitting facet of the semiconductor portion is less than a second distance between the submount and the rear facet of the semiconductor portion.

A light emitting device includes a plurality of semiconductor laser elements, a light-transmissive member, and a wavelength conversion member. Each of the semiconductor laser elements is configured to emit light having a first wavelength. The light-transmissive member includes a plurality of first inclined surfaces and a lower surface. The light-transmissive member is positioned with respect to the semiconductor laser elements so that beams of the light emitted from the semiconductor laser elements enter the light-transmissive member respectively through the first inclined surfaces and exit from the lower surface. The wavelength conversion member is disposed in contact with the lower surface of the light-transmissive member and configured to convert at least a portion of the light exiting from the lower surface to wavelength-converted light having a second wavelength.

A light source device includes: a plurality of light sources that generate rays of light with different wavelengths corresponding to a plurality of target wavelengths located on a designated wavelength grid; a plurality of photodetectors that detect output powers of the plurality of light sources; a plurality of optical bandpass filters that are provided between the plurality of light sources and the plurality of photodetectors; a temperature adjustment unit that adjusts a temperature of an area around the plurality of light sources; and a processor that controls the temperature adjustment unit based on output signals of the plurality of photodetectors. Widths of passbands of the optical bandpass filters are less than a wavelength spacing in the wavelength grid.

Top emitting vertical cavity surface emitting lasers (VCSELs) are described with various top side optical gratings, etched into and/or fabricated over the VCSELs, to configure optical emission properties to suite a wide range of applications. Top side gratings are configured for spanning one or multiple emitters in any desired alignment/misalignment, using a wide range of refractive index materials and arrangements, levels of dimensionality (1D, 2D or 3D), forms of chirping of the grating, various grating periods, transmissive/reflective properties and in-plane coupling, ranges of diffractive orders, different relative amplitudes of transmitted and reflected orders, different polarizations, different levels of collimation, different levels of divergence, different diffraction and reflection, different beam diffusion, fixed or varied rotation of optical output, and far field engineering of the optical output.