摘要:
The invention provides a laser structure that operates at a wavelength of 1.3 &mgr;m and at elevated temperatures and a method of making same. The laser structure includes a quantum well layer of InAsP. The quantum well layer is sandwiched between a first barrier layer and a second barrier layer. Each barrier layer exhibits a higher bandgap energy than the quantum well layer. Also, each barrier layer comprises Gax(AlIn)1−xP in which x 0. This material has a higher bandgap energy than conventional barrier layer materials, such as InGaP. The resulting larger conduction band discontinuity leads to improved high temperature performance without increasing the threshold current of the laser structure.
摘要:
The present invention provides a n-drive surface emitting laser comprised of an active region, a first mirror region having a first conductivity type, a second mirror region having a second opposite conductivity type, the first and second mirror regions being located on opposite sides of the light generation region, a buffer region having a second conductivity type, and a substrate having a first conductivity type. In the preferred embodiment the first conductivity type is n-type, thus the present invention provides a method of forming an n-drive semiconductor laser on an n-type substrate. Contact is made to the p-type mirror region via a tunnel junction formed by degeneratively doping the areas of the substrate region and the buffer region which abut each other. The tunnel junction is reverse biased so that current is injected through the degeneratively doped p-n junction formed by the n+ substrate and the p-type conducting layer.
摘要:
A semiconductor laser diode includes a first buffer layer, a second buffer layer and an active layer sandwiched between the two buffer layers. The active layer contains dopant ions where the dopant ions are such that energy transfer between the unimplanted material in the active layer and the dopant ions implanted causes lasing action substantially at a single frequency characteristic of the dopant ions. The two buffer layers confine light emitted by the active layer. The second buffer layer is grown epitaxially on the active layer. In the preferred embodiment, the structure is made by first growing a thin second buffer layer epitaxially on the active layer. The dopant ions are then implanted into the active layer through the thin second buffer layer. The structure is heated to a high temperature to anneal the structure and to activate the dopants. The second buffer layer is then further grown to make it thicker so as to be more effective in confining the light emission in the active layer.
摘要:
In accordance with an aspect of the invention, a system has a transmitter and a receiver, where the transmitter includes a beam source and an optical element. The beam source produces a beam that represents information, and the optical element alters the beam so that the beam has a uniform intensity over a cross-sectional area. The receiver is separated from the transmitter by free space through which the beam propagates and includes an active area positioned to receive a portion of the beam that the receiver converts into a received signal. To accommodate possible misalignment, the cross-sectional area of the beam is larger than the active area by an amount that accommodates a range of misalignment of the receiver with the transmitter.
摘要:
In accordance with the invention, increased maximum modulation speeds and improved hole distribution are obtained for light emitting devices. Barrier layers of a quantum well structure for a light emitting device are formed with varying barrier energy heights. Quantum well layers of the quantum well structure are formed between the barrier layers.
摘要:
The present invention provides a ring laser system comprising forming an optical core by an epitaxial layer overgrowth over an intermediate layer, forming multi-quantum wells adjacent to the optical core and forming an outer structure further comprising a total internal reflector, wherein forming photons within the multi-quantum wells further comprises circulating the photons within the ring laser structure comprising the outer structure, the multi-quantum wells, and the optical core.
摘要:
An optical isolator for coupling light from a first waveguide to a second waveguide is disclosed. The optical isolator utilizes a resonator coupled to the first and second optical waveguides. The resonator has a resonance at λ for light traveling from the first optical waveguide to the second optical waveguide; however, the resonator does not have a resonance at λ for light traveling from the second waveguide to the first waveguide. The resonator can use a layer of ferromagnetic material in an applied magnetic field. The magnetic field within the ferromagnetic material varies in strength and/or direction over the layer of ferromagnetic material. The magnetic field can be generated by an external magnetic field that varies over the layer of ferromagnetic material. Alternatively, the resonator can include a layer of ferromagnetic metal that overlies a portion of the layer of ferromagnetic material and a constant external magnetic field.
摘要:
The tunnel junction structure comprises a p-type tunnel junction layer of a first semiconductor material, an n-type tunnel junction layer of a second semiconductor material and a tunnel junction between the tunnel junction layers. At least one of the semiconductor materials includes gallium (Ga), arsenic (As) and either nitrogen (N) or antimony (Sb). The probability of tunneling is significantly increased, and the voltage drop across the tunnel junction is consequently decreased, by forming the tunnel junction structure of materials having a reduced difference between the valence band energy of the material of the p-type tunnel junction layer and the conduction band energy of the n-type tunnel junction layer.
摘要:
The active region of a long-wavelength light emitting device is made by providing an organometallic vapor phase epitaxy (OMVPE) reactor, placing a substrate wafer capable of supporting growth of indium gallium arsenide nitride in the reactor, supplying a Group III–V precursor mixture comprising an arsenic precursor, a nitrogen precursor, a gallium precursor, an indium precursor and a carrier gas to the reactor and pressurizing the reactor to a sub-atmospheric elevated growth pressure no higher than that at which a layer of indium gallium arsenide layer having a nitrogen fraction commensurate with light emission at a wavelength longer than 1.2 μm is deposited over the substrate wafer.
摘要:
Light-emitting devices are described. One example of a light-emitting device includes a first barrier layer and a second barrier layer, and a quantum well layer located between the first and second barrier layers. The first and second barrier layers are composed of gallium arsenide, and the quantum well layer is composed of indium gallium arsenide nitride. A first layer is located between the quantum well layer and the first barrier layer. The first layer has a bandgap energy between that of the first barrier layer and that of the quantum well layer. Another example of a light-emitting device includes a quantum well and a carrier capture element adjacent the quantum well. The carrier capture element increases the effective carrier capture cross-section of the quantum well.