A laser comprising a laser cavity formed by a broadband mirror and a comb mirror having a plurality of reflection peaks. A spacing between the plurality of reflection peaks is adjusted such that only one reflection peak is in a gain bandwidth of the laser.

A semiconductor laser is for generating colored light. The semiconductor laser oscillates in a longitudinal multimode. A width of a wavelength band with an intensity equal to or more than 20 dB relative to a peak intensity in a spectrum distribution of output light is equal to or less than 15 nm. A light source device may include The semiconductor laser; a wavelength estimating device configured to estimate a wavelength of light from the semiconductor laser; and an emission-light intensity setting unit configured to set an emission light intensity of the semiconductor laser in accordance with an estimation result by the wavelength estimating device.

A tunable external resonator laser is mode-hop-free for broadband and has a laser chip which emits light; a lens which collimates the light emitted from the laser chip, a diffraction grating which diffracts the light collimated by the lens, a support body to which the diffraction grating is fixed, and a movable mirror which reflects the light diffracted by the diffraction grating, wherein the diffraction grating is arranged a prescribed distance apart from a Littman-type tunable external resonator laser arrangement in which the movable mirror rotates on a pivot which is the intersection point of the surface of said movable mirror and the surface of the diffraction grating.

This disclosure describes a multi-junction laser diode with improved wavelength stability. The multi-junction laser diode is found in an edge emitting laser (EEL). The disclosed system and method are suited for improving the wavelength stability of multi-junction EEL without coupling the laser modes of the individual junctions and without using any external elements such as Fiber Bragg Gratings (FBR), Volume Bragg Gratings (VBG) or Thermoelectric Cooling (TEC).

A semiconductor laser resonator configured to generate a laser beam includes a gain medium layer including a semiconductor material and comprising at least one protrusion formed by at least one trench to protrude in an upper portion of the gain medium layer. In the semiconductor laser resonator, the at least one protrusion is configured to confine the laser beam as a standing wave in the at least one protrusion.

A control circuit in this laser equipment drives a drive circuit of a photonic crystal laser element under a predetermined condition. It was found that a wavelength width of a laser beam to be output from the photonic crystal laser element is dependent on a standardized drive current k and a pulse width T, and had a predetermined relationship with these. By meeting this condition, a laser beam with a plurality of wavelengths can be controlled and output.

A laser apparatus includes light source elements outputting laser beams; a wavelength-selecting element disposed in an optical path of each of the laser beams and configured to cause light in a predetermined wavelength band to selectively transmit therethrough; and a partially transmissive-reflector that receives the light transmitted through the wavelength-selecting element, reflects a part of the input light toward the wavelength-selecting element, and causes its remainder to transmit therethrough. The wavelength-selecting element causes a part of the respective laser beams output from the respective light source elements to selectively transmit therethrough, the partially transmissive-reflector reflects a part of the respective transmitted laser beams, and the wavelength-selecting element causes a part of the respective reflected laser beams to transmit to return to the light source elements, and each of the light source elements preferentially oscillates at a wavelength of the laser beam that transmits through the wavelength-selecting element.

A VCSEL array having a plurality of VCSELs, each having more than two modes, and the optical emission from each of the VCSELs overlaps in a far field of the VCSELs. A VCSEL array having a plurality of VCSELs, each having an aperture size of at least about 6 ?m, and the optical emission from each of the VCSELs overlaps in a far field of the VCSELs. A VCSEL array having a plurality of VCSELs, wherein the spectral width of each VCSEL is at least about 0.5 nm, and the optical emission from each of the VCSELs overlaps in a far field of the VCSELs.

A VCSEL package including a VCSEL, a housing, containing the VCSEL, and a diffuser operably attached to the housing and configured to receive an emitted beam of light from the VCSEL and produce a beam of predetermined angular divergence. The housing may be a PLLC package, a ceramic package, or a TO-style package. The diffuser could be a substantially planar diffuser sheet, which in some cases may be comprised of glass or plastic. In some embodiments, the diffuser could be a diffractive optical element or holographic light shaping diffuser. In some embodiments, the diffuser can be designed to produce a beam with an illumination full angle of up to about 90 degrees.

A laser comprising a laser cavity formed by a broadband mirror and a comb mirror having a plurality of reflection peaks. A spacing between the plurality of reflection peaks is adjusted such that only one reflection peak is in a gain bandwidth of the laser.