摘要:
A solid-state, surface-emitting, optical device such as a LED or VCSEL has a body of optical gain medium (18) overlying a high reflectivity distributed Bragg reflector (DBR) mirror (14) which is carried on part of an underlayer (13). The gain medium (18) is part of an epitaxial layered structure (15) extending from the underlayer (13) and over the mirror (14).
摘要:
The present invention relates to a special type of Distributed Bragg Reflectors (DBRs). The present invention also relates to semiconductor semiconductor resonant cavity devices for emitting or absorbing light. A DBR for reflecting radiation with a wavelength λ, according to the present invention, includes at least one mirror pair. Each mirror pair comprises a bottom layer and a top layer, the top layer of one mirror pair comprising gallium phosphide (GaP) and having an optical thickness of substantially an odd multiple of λ/4. A resonant cavity device (40) for emitting or absorbing light with a wavelength λ, according to the present invention, comprises a first mirror (44) and a second mirror (68) with an active region (54) located therebetween. The second mirror (68) comprises a stack of DBRs including at least one mirror pair (69, 70), the mirror pair (69, 70) having at least a top layer (70) and a bottom layer. The top layer (70) is the layer most remote from the first mirror (44), and this layer is essentially composed of gallium phosphide (GaP) and has an optical thickness of substantially an odd multiple of λ/4. The present invention also provides a method of manufacturing a resonant cavity device for emitting or absorbing light with a wavelength λ.
摘要:
A light emitting diode (LED) (10) grown on a substrate (16) doped with one or more rare earth or transition element. The dopant ions absorb some or all of the light from the LED's active layer (11), pumping the electrons on the dopant ion to a higher energy state. The electrons are naturally drawn to their equilibrium state and they emit light at a wavelength that depends on the type of dopant ion. The invention is particularly applicable to nitride based LEDs (10) emitting UV light and grown on a sapphire substrate (16) doped with chromium. The chromium ions absorb the UV light, exciting the electrons on ions to a higher energy state. When they return to their equilibrium state they emit red light and some of the red light will emit from the LED's surface.
摘要:
Diode lasers are fabricated whose performance is essentially unchanged over designed temperature and bias ranges. The threshold current (Ith) and the external efficiency (θext) of the diode lasers are unchanged over a range of specified temperatures.
摘要:
A mirror (31) for use in a semiconductor laser comprises four or more alternating layers of a low refractive index semiconductor material having an index of refraction of n 1 and a high refractive index semiconductor material having an index of refraction of n 2 where n 2 > n 1 . A first one (211) of the layers is grown at a temperature, referred to as the "low temperature", such that the layer is in a substantially amorphous state, and a second one (221) of the layers is grown at a temperature, referred to as the "high temperature", such that the layer is in a substantially monocrystalline state. The first one of the layers and the second one of the layers correspond to layers having different indices of refraction. The thickness, T L , of the layer grown at the low temperature satisfiesTL={λ/(4 × nL)} (2M - 1) L is the refractive index of the layer grown at the low temperature, and M is a positive integer. The thickness, T H , of the layer grown at the high temperature satisfiesTH={λ/(4 × nH)} (2N - 1) > 0.2 µm where n H is the refractive index of the layer grown at the high temperature, and N is a positive integer. The first and second materials are preferably Group III-V nitrides such as Al x Ga 1-x N, where x = 0.3 to 1, and GaN.
摘要:
L'invention concerne un réflecteur optique en semiconducteur destiné notamment à être disposé en regard d'une cavité laser intégrée pour réalimenter cette dernière et permettre son oscillation en continu. Le réflecteur comprend plusieurs sections (Si, S i+1 ) de réflecteur de Bragg en cascade. Il est plus particulièrement caractérisé en ce que lesdites sections sont de même longueur L et ont un même coefficient de couplage (κ), et en ce que la longueur L de chacune desdites sections est donnée par la relation suivante : L = λ 2 / [ (n i+1 + n i ) x 1,7(n i+1 Λ i+1 - n i Λ i )] où λ est la valeur moyenne des longueurs d'ondes de Bragg réfléchies par le réflecteur, n i+1 et n i sont les indices de réfraction effectifs respectivement desdites sections adjacentes (S i+1 , S i ), et Λ i+1 et Λ i sont les périodes respectivement desdites sections adjacentes (S i+1 , S i )· Le réflecteur selon l'invention présente une large fenêtre spectrale, indépendante de la valeur du coefficient de couplage.
摘要:
Dual wavelength monolithically integrated VCSELs and a method of fabrication for emitting a short wavelength light (63) and a long wavelength light (64) including a first mirror stack (14) lattice matched to the surface (13) of a substrate (12). A short wavelength VCSEL (10) is fabricated and masked during the formation of a long wavelength VCSEL (34). Each VCSEL (10 & 34) further including mirror pairs (15 & 16) in a AlAs/AlGaAs material system, an active region (22 & 35) lattice matched to a surface of the first mirror stack (14), and a second mirror stack (38 & 40) lattice matched to a surface of the active region (22 & 35) and capable of emitting either a short wavelength light (63) or a long wavelength light (64), dependent upon design parameters. Electrical contacts (52, 53, 54, 56, 57, 58, & 59) are coupled to the active regions (22) of the monolithically integrated short wavelength VCSEL (10) and the long wavelength VCSEL (34). The dual wavelength monolithically integrated VCSELs fabricated as a semiconductor laser chip (50) capable of read/write applications for both CDs and DVDs.
摘要:
A hybrid mirror structure for a visible emitting VCSEL (101) including a first distributed Bragg reflector (106) disposed on a substrate (102) and including first pairs (108) of alternating layers (111, 113) including an oxidized aluminum material and second pairs (116) of alternating layers (118, 119). A first cladding region (123) disposed on the first distributed Bragg reflector (106), an active region (126) disposed on the first cladding region (123), and a second cladding region (128) disposed on the active region (126), and a second distributed Bragg reflector (131) disposed on the second cladding region (128). In the first distributed Bragg reflector (106), each pair (108) of alternating layers (111, 113) includes a layer (111) containing oxidized aluminum, which is oxidized to decrease the index of refraction to a range of approximately 1.3 to 1.7.
摘要:
A delta doped layer is used at a heterointerface semiconductor mirror in a vertical cavity laser to reduce the series resistance of the laser. The layer, in a preferred embodiment, is in the mirror having p-type conductivity, because of the greater resistance in the p-type region than in the n-type region.