A tunable laser that includes an array of parallel optical amplifiers is described. The laser may also include an intracavity NM coupler that couples power between a cavity mirror and the array of parallel optical amplifiers. Phase adjusters in optical paths between the NM coupler and the optical amplifiers can be used to adjust an amount of power output from M1 ports of the NM coupler. A tunable wavelength filter is incorporated in the laser cavity to select a lasing wavelength.

Disclosed are photonic particles and methods of using particles in biological samples. The particles are configured to emit laser light when energetically stimulated by, e.g., a pump source. The particles may include a gain medium with inorganic materials, an optical cavity with high refractive index, and a coating with organic materials. The particles may be smaller than 3 microns along their longest axes. The particles may attach to each other to form, e.g., doublets and triplets. The particles may be injection-locked by coupling an injection beam into a particle while pumping so that an injection seed is amplified to develop into laser oscillation. A microscopy system may include a pump source, beam scanner, spectrometer with resolution of less than 1 nanometer and acquisition rate of more than 1 kilohertz, and spectral analyzer configured to distinguish spectral peaks of laser output from broadband background.

A laser source for emitting radiation in a given emission spectral band, centered on a given emission angular frequency, the central emission angular frequency is provided. The laser source comprises a laser cavity comprising a gain section having a known frequency dependent Group Delay Dispersion, and a GTI mirror arranged at one end of the gain section, having a known frequency dependent Group Delay Dispersion. The gain section and the GTI mirror are formed into a same laser medium, the laser medium having a known frequency dependent Group Delay Dispersion, and the gain section and the GTI mirror are separated by a gap of predetermined width filled with a dielectric medium thus forming a two parts laser cavity. Further, the GTI GDD at least partly compensates the sum of the Gain GDD and the material GDD in the emission spectral band.

A semiconductor laser device includes an optical waveguide that extends toward a first end of the semiconductor laser device. The optical waveguide includes a first clad layer, an active layer, a second clad layer, and an electrode layer in this order. A reflecting surface, which has a dielectric film and a metal film in this order from the active layer, crosses the active layer at a second end of the optical waveguide.

Practical silicon-based light sources are still missing, despite the progress in germanium lasers, because both silicon and germanium are indirect-band semiconductors and inefficient at light generation. A tunable and single mode external cavity laser comprising: a gain medium for generating light between a reflective surface at one end of the gain medium; and a wavelength selective reflector at the other end of a laser cavity. A splitter disposed in the laser cavity includes an input port optically coupled to the gain medium, an input/output port optically coupled to the wavelength selective reflector, and an output port for outputting laser light at selected wavelengths. The wavelength selective reflector reflects light of one or more selected periodic wavelengths back to the gain medium via the input/output port, and passes light of non-selected wavelengths out of the laser cavity.

A apparatus includes a tunable laser configured to include a tunable filter and a mirror; a first optical splitter provided between the tunable filter and the mirror, the first optical splitter including a first port and a second port on a tunable filter side and a third port and a fourth port on a mirror side, in which the tunable filter is coupled to the first port and the mirror is coupled to the third port, respectively; a first optical waveguide coupled to the second port; a second optical waveguide coupled to the fourth port; and an optical coupler with which the first optical waveguide and the second optical waveguide are combined.

A mode-locked semiconductor laser capable of changing the spacing between the carrier frequencies of its output comb. In an example embodiment, the mode-locked semiconductor laser is implemented as a hybrid solid-state device comprising a III-V semiconductor chip and a silicon chip attached to one another to form a laser cavity. The III-V semiconductor chip includes a gain medium configured to generate light in response to being electrically and/or optically pumped. The silicon chip includes a plurality of optical waveguides arranged to provide multiple optical paths of different effective lengths for the light generated in the laser cavity. Different optical paths can be controllably selected, using one or more optical switches connected between the optical waveguides, to change the effective optical length of the laser cavity and, as a result, the output-comb frequency spacing. In some embodiments, the output-comb frequency spacing can be changeable at least by a factor of 1.5.

Disclosed herein are various embodiments for laser apparatuses. In an example embodiment, the laser apparatus comprises (1) a laser-emitting epitaxial structure having a front and a back, wherein the laser-emitting epitaxial structure is back-emitting and comprises a plurality of laser regions within a single mesa structure, each laser region having an aperture through which laser beams are controllably emitted, (2) a micro-lens array located on the back of the laser-emitting epitaxial structure, wherein each micro-lens of the micro-lens array is aligned with a laser region of the laser-emitting epitaxial structure, and (3) a non-coherent beam combiner positioned to non-coherently combine a plurality of laser beams emitted from the apertures.

A laser module that can suppress influence due to a reflected light between chips is provided. A laser module 100 according to one embodiment of the present invention includes: a laser element 110 provided on a first substrate and having a laser oscillation unit that generates a laser light and a first optical waveguide that guides the laser light; and an optical amplifier 120 provided on a second substrate and having a second waveguide that guides the laser light. The first optical waveguide is nonparallel relative to an end face of the first substrate and connected thereto, the second optical waveguide is nonparallel relative to an end face of the second substrate and connected thereto, and the first substrate and the second substrate are arranged such that the laser light output from the first optical waveguide is optically coupled to the second optical waveguide.

A tunable laser that includes an array of parallel optical amplifiers is described. The laser may also include an intracavity NM coupler that couples power between a cavity mirror and the array of parallel optical amplifiers. Phase adjusters in optical paths between the NM coupler and the optical amplifiers can be used to adjust an amount of power output from M1 ports of the NM coupler. A tunable wavelength filter is incorporated in the laser cavity to select a lasing wavelength.