A light emitting element includes a laminated structure 20 in which a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22 are laminated, a first light reflecting layer 41, and a second light reflecting layer 42 having a flat shape, a base surface 90 located on a side of a first surface of the first compound semiconductor layer 21 has a first region 91 (upwardly convex first-A region 91A and first-B region 91B) including a protruding portion protruding in a direction away from the active layer and a second region 92 having a flat surface, the first light reflecting layer 41 is formed at least on the first-A region 91A, a second curve formed by the first-B region 91B and a straight line formed by the second region 92 intersects at an angle exceeding 0°, and the second curve includes at least one kind of figure selected from the group consisting of a combination of a downwardly convex curve, a line segment, and an arbitrary curve.

A single-mode micro-laser based on a single whispering gallery mode optical microcavity and a preparation method thereof described includes: preparing a desired single whispering gallery mode optical microcavity doped with rare earth ions or containing a gain material such as quantum dots, wherein an optical microcavity configuration include a micro-disk cavity, a ring-shaped microcavity, and a racetrack-shaped microcavity; a material type include lithium niobate, silicon dioxide, silicon nitride, etc.; preparing an optical fiber cone or an optical waveguide of a required size which can excite high-order modes of the optical microcavity, such as a ridge waveguide and a circular waveguides; and coupling, integrating, and packaging the optical fiber cone or the optical waveguide with the microcavity. A pump light is coupled to the optical fiber cone or the optical waveguide to excite a compound mode with a polygonal configuration.

A light emitting element (10A) of the present disclosure includes: a stacked structure (20) in which a first compound semiconductor layer (21) having a first surface (21a) and a second surface (21b), an active layer (23), and a second compound semiconductor layer (22) having a first surface (22a) and a second surface (22b) are stacked; a first light reflecting layer (41) formed on a first surface side of the first compound semiconductor layer (21) and having a convex shape in a direction away from the active layer (23); and a second light reflecting layer (42) formed on a second surface side of the second compound semiconductor layer (22) and having a flat shape, in which a partition wall (24) extending in a stacking direction of the stacked structure (20) is formed so as to surround the first light reflecting layer (41).

Single-mode distributed-feedback (DFB) lasers including single mode DFB waveguides with tapered grating structures are provided herein. Tapered grating structures provide for single mode DFB waveguides with predictable single mode operation. Uniform grating structures may provide for single mode operation, however DFB waveguides implementing uniform grating structures may operate at one of two single modes. Advantageously, DFB waveguides with tapered gratings operate with a spectrally narrow single mode at the same predictable single mode for all DFB waveguides with substantially identical specifications. Such predictability may lead to increased yield during manufacture of DFB waveguides with tapered gratings.

A laser resonator includes an active material, which amplifies light associated with an optical gain of the resonator, and passive materials disposed in proximity with the active material. The resonator oscillates over one or more optical modes, each of which corresponds to a particular spatial energy distribution and resonant frequency. Based on a characteristic of the passive materials, for the particular spatial energy distribution corresponding to at least one of the optical modes, a preponderant portion of optical energy is distributed apart from the active material. The passive materials may include a low loss material, which stores the preponderant optical energy portion distributed apart from the active material, and a buffer material disposed between the low loss material and the active material, which controls a ratio of the optical energy stored in the low loss material to a portion of the optical energy in the active material.

The invention relates to an athermalized device for generating laser radiation that is focused in a focal point, comprising a lens and a plastic housing and a passive adjustment system for adjusting the object distance S1. The passive adjustment device has an effective coefficient of thermal expansion (I)

[00001]${\alpha }_V=\frac{s_1}{f}.Math.\left[{\alpha }_L-\frac{1}{n-1}.Math.\left(\frac{\partial n}{\partial \lambda }.Math.\frac{d\lambda }{\mathrm{dT}}+\frac{\partial n}{\partial T}\right)\right]+{\alpha }_2.Math.\left(1-\frac{s_1}{f}\right).$

A semiconductor device comprising: a layered structure 20 configured by layering a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22; a substrate 11; a first light reflecting layer 41 arranged on the first surface side of the first compound semiconductor layer 21; and a second light reflecting layer 42 arranged on the second surface side of the second compound semiconductor layer 22, wherein the second light reflecting layer 42 has a flat shape; a concave surface portion 12 is formed on a substrate surface 11b; the first light reflecting layer 41 is formed on at least the concave surface portion 12; the first compound semiconductor layer 21 is formed to extend from the substrate surface 11b onto the concave surface portion 12; and a cavity is present between the first light reflecting layer 41 formed on the concave surface portion 12 and the first compound semiconductor layer 21.

The invention relates to an edge-emitting semiconductor laser diode, having: —a semiconductor layer sequence, which comprises a bottom surface, a ridge waveguide on a top surface facing away from the bottom surface, and a side surface which is arranged transverse to the top surface, and —a first recess, which extends from the bottom surface to the top surface, wherein —a first region of the semiconductor layer sequence is removed from the side surface in the region of the first recess. The invention further relates to a method for producing a plurality of edge-emitting semiconductor laser diodes.

A laser comprising a narrow linewidth, comprising: a grating along a laser cavity; a laser waveguide having a plurality of waveguide sections corresponding to a plurality of grating sections, each of the plurality of waveguide sections having a ridge/mesa width for detuning the grating in each of the plurality of grating sections; and a plurality of contact electrodes contacting each of the plurality of waveguide sections, the plurality of contact electrodes for applying a different current to each of the plurality of waveguide sections to enable active feedback noise suppression.

An on-chip ultra-narrow linewidth laser and a method for obtaining a single-longitudinal mode ultra-narrow linewidth optical signal are provided in the present invention. The on-chip ultra-narrow linewidth laser includes a laser generating gain unit for generating a broad-spectrum initial optical signal and performing wavelength filtering on the generated optical signal, and also includes a distributed scattering feedback unit for performing linewidth compression on the optical signal; the laser generating gain unit is connected with the distributed scattering feedback unit, so that the optical signal generated by the laser generating gain unit is subjected to wavelength filtering and then output to the light guide component of the distributed scattering feedback unit to scatter to form an optical signal with a narrower linewidth to achieve linewidth compression, and the optical signal returning along the original path and fed back to the optical signal of the laser generating gain unit is subjected to gain amplification and wavelength filtering once again, repeating until achieving a steady state so as to obtain a single-longitudinal mode ultra-narrow linewidth optical signal. The laser can obtain a steady single-longitudinal mode ultra-narrow linewidth optical signal, and is simple in structure and small in volume.