摘要:
In an embodiment, a distributed Bragg reflector (DBR) laser includes a gain section and a passive section. The gain section includes an active region, an upper separate confinement heterostructure (SCH), and a lower SCH. The upper SCH is above the active region and has a thickness of at least 60 nanometers (nm). The lower SCH is below the active region and has a thickness of at least 60 nm. The passive section is coupled to the gain section, the passive section having a DBR in optical communication with the active region.
摘要:
A heterostructure self-pulsating laser device (1) comprising an active layer (5) with first and second cladding layers (6, 7) on respective opposite sides of the active layer (5) is grown on an n-substrate (2) of indium phosphide, the second cladding layer (7) being grown on the substrate (2), the active layer (5) being grown on the second cladding layer (7), and the first cladding layer (6) being grown on the active layer (5). A current blocking layer (12) is formed in the first cladding layer (6) and divides the first cladding layer (6) to form a distal cladding layer (15) and a proximal cladding layer (16) adjacent the active layer (5). A channel (14) defined by the current blocking layer (12) confines the current in the first cladding layer (6) and determines the width of the active light generating area of the active layer (5). The first and second cladding layers (6, 7) and the current blocking layer (12) are of grown doped indium phosphide. The first cladding layer (6) is doped to be a p-type layer and the second cladding layer (7) and the current blocking layer (12) are doped to be of n-type. The level of dopant in the current blocking layer (12) is approximately ten times greater than the level of doping in the first cladding layer (6) in order to establish an effective refractive index step in the lateral direction of the active layer (5) in order to confine light generated in the active layer (5). A continuous wave operating laser device is also described.
摘要:
The invention discloses improved structures of light-processing (e.g., light-emitting and light-absorbing/sensing) devices, in particular Vertical Cavity Surface Emitting Lasers (VCSELs), such as may find use in telecommunications applications. The disclosed VSCAL devices and production methods provide for an active region having a quantum well structure grown on GaAs-containing substrates, thus providing processing compatibility for light having wavelength in the range 1.0 to 1.6 mu m. The active region structure combines strain-compensating barriers with different band alignments in the quantum wells to achieve a long emission wavelength while at the same time decreasing the strain in the structure. The improved functioning of the devices disclosed results from building them with multicomponent alloy layers having a large number of constituents. The invention discloses as a key constituent in the proposed alloy layers for the active region a substance, such as nitrogen (N), suitable for reducing bandgap energy (i.e., increasing light wavelength) associated with the layers, while at the same time lowering the lattice constant associated with the structure and hence lowering strain.
摘要:
An optical, semiconductor micro-resonator device includes a microcavity resonator (12) and a pair of adjacent waveguides (14, 16). The microactivity resonator has a curved diameter of approximately 56000*lambda.lg/n.res or less where lambda.lg is the longest operating wavelength of light and n.res is the propagating refractive index. Light propagating in the first waveguide (14) with a wavelength on resonance with the microcavity resonator is coupled to the second waveguide (16) for output therefrom. Light propagating in the first waveguide (14) with a wavelength that is off resoance with the microcavity resonator continues to propagate in the first waveguide (14) for output therefrom.
摘要:
The invention relates to a radiation-emitting semiconductor diode, in particular a laser (amplifier) diode, of the buried hetero type which comprises at least one separate confinement layer (4) lying between the active layer (2) and one of the InP cladding layers (1, 3). The active region (2A) has an emission wavelength above 1 mu m and forms part, as do the separate confinement layer (4) and the InP cladding layers (1, 3), of the strip-shaped region (30) which is surrounded by a current-blocking third cladding layer (5) of InP. A disadvantage of the known diode is that its starting current rises comparatively strongly in time, so that the useful life of the diode is limited and indeed too short. In a diode according to the invention, the separate confinement layer (4) comprises an aluminum-containing semiconductor material with at most 30 % aluminum, and preferably at most 20 % aluminum, or an aluminum-free semiconductor material. The short life of the known diode was caused by the presence of oxygen-containing material on the lateral sides of the separate confinement layer (4) adjoining the third cladding layer (5). The degradation is related to the aluminum content of the separate confinement layer (4). Preferably, the separate confinement layer (4) comprises AlGaInAs or GaInAsP. The bandgap and refractive index of the separate confinement layer may have flat, stepped, or gradual profiles. The invention also relates to a method of manufacturing a diode according to the invention.
摘要:
An optical transmission link has both a transmitter module and a receiver module operable under uncooled conditions, i.e., without the need of costly cooling equipment, such as thermoelectric coolers. The optical transmission system includes both a semiconductor laser diode source and an optical receiver module that are both designed to operate uncooled under high frequencies (e.g., GHz range) over a wide temperature range without significant changes in signal bandwidth and at temperatures in excess of 125 DEG C. Compensation is provided to reduce the effect of photodiode noise and amplifier noise. In addition, temperature compensation can be provided that provides for overall reduction in receiver noise across the bandwidth of the receiver module through maintenance of a temperature environment optimizing receiver performance.
摘要:
Disclosed is a method of forming a laser source capable of producing mid-IR laser radiation comprises growing a first core structure on a substrate, etching away the first core structure in one or more locations, and growing a second core structure on the substrate. At least one of the core structures comprises a quantum cascade gain medium emitting at a frequency within the range from 3-14 μm. Also disclosed is a laser source capable of producing mid-IR laser radiation comprising a quantum- cascade core positioned on a substrate for emitting within the range from 3-14 μm and a second core on the substrate positioned in-plane relative to the first core. The second core is one of a) a passive waveguide core b) a second quantum-cascade core and c) a semiconductor active core region.
摘要:
Semiconductor quantum well devices and methods of making the same are described. In one aspect, a device includes a quantum well structure (38) that includes semiconductor layers (40-52) defining interleaved heavy-hole and light-hole valance band quantum wells. Each of the quantum wells includes a quantum well layer interposed between barrier layers. One of the semiconductor layers that functions as a barrier layer of one of the light-hole quantum wells (60, 62) also functions as the quantum well layer of one of the heavy-hole quantum wells (54, 56, 58). Another of the semiconductor layers that functions as a barrier layer of one of the heavy-hole quantum wells (54, 56, 58) also functions as the quantum well layer of one of the light-hole quantum wells (60, 62).