Abstract: A phototherapy device, a kit containing such a phototherapy device, and a method for treating a patient with a phototherapy device, the phototherapy device containing a housing, an emission portion, and a light tube, the housing containing a light source that emits light at a wavelength of from about 400 nm to about 550 nm, and may contain a light shield proximal to the light source, the emission portion being distal form the housing and connected thereto via a light tube which contains an optical fibre, and a mesh that may enclose the optical fibre and may allow a limited amount of light to leak from the optical fibre to the outside environment.
Type:
Grant
Filed:
December 18, 2019
Date of Patent:
December 21, 2021
Assignee:
AVALON PHOTONICS (HK) LIMITED
Inventors:
Sai Keung Chow, Chun Lung Choi, Chi Yeung Mang, Chun Ho Wong, Johnson Yiu-Nam Lau
Abstract: A design of a vertical cavity surface emitting laser chip suitable for high speed data communication. An intracavity contact to the doped layers of the bottom mirror is formed so that both contacts are on the top epitaxial side of the wafer. These main structural features can be used to reduce the bond pad capacitance by a suitable spatial separation of metallizations of the p and n contact. The bond pads are processed as a short symmetric coplanar line in a ground signal ground configuration which allows flexible device testing and packaging. A significant capacitance between the pads of the center strip and the outer ground strips is avoided by etching the doped semiconductor layers between these strips down to the semi-insulating substrate. This design avoids pad metallizations and the corresponding critical photolithographic steps over large height differences from the vertical cavity surface emitting laser mesa top to the substrate.
Abstract: A method is disclosed in which the principle of phase-coupling is used to stabilize the polarization of laser radiation emitted by a plurality of phase-coupled vertical cavity surface emitting laser elements. Due to a suitable coupling strength between adjacent VCSEL elements, the probability of polarization flips of VCSEL devices operated in the single mode region is zero or at least drastically reduced. Moreover, a VCSEL device is disclosed, comprising a polarization adjusting means for controlling the polarization direction of an arrangement of a plurality of phase-coupled VCSEL elements, wherein the polarization direction of each VCSEL element is substantially kept constant.
Abstract: A vertical-cavity surface-emitting laser comprises one or more quantum well layers and one or more barrier layers to define an gain region, a first mirror means and a second mirror means, wherein the first and second mirror means define a resonator. Moreover, the vertical-cavity surface-emitting laser further comprises a first indium phosphide layer adjacent to the gain region and a second indium phosphide layer adjacent to the gain region to define a laser cavity.
Abstract: A vertical-cavity surface-emitting laser device (VCSEL) comprises a plurality of VCSEL elements arranged on a common substrate, each VCSEL element comprising first mirror means and second mirror means, each having a predefined reflectivity at a predetermined wavelength, for forming an optical resonator for said wavelength, and a laser active region disposed between said first and second mirror means. In addition, the VCSEL device comprises a grid layer having a plurality of openings corresponding to the respective VCSEL elements and a contact layer having a predetermined thickness, said contact layer being interposed between each of said first mirror means and said grid layer, wherein an optical thickness of said contact layer and a reflectivity and an absorption of said grid layer is selected so as to provide an effective reflectivity of each of said first mirror means depending on said grid layer and being different for areas covered by the grid and areas corresponding to said grid openings.
Type:
Grant
Filed:
November 17, 2000
Date of Patent:
January 14, 2003
Assignee:
Avalon Photonics
Inventors:
Elyahou Kapon, Fabrice Monti di Sopra, Marcel Brunner
Abstract: A vertical-surface-emitting laser comprises: a first reflector and a second reflector arranged to define a laser resonator extending along a longitudinal direction and along transverse directions, a laser active region located between the first and second reflectors, a metal layer at the first or second reflectors and patterned to form a radiation emission window, and a phase matching layer arranged within the resonator and having an optical thickness adapted to transversely pattern a reflectivity of the first and/or second reflectors. The VCSEL device may further comprise an aperture formed between the first and second reflectors. The mode selectivity of the VCSEL is substantially determined by a reflectivity difference defined by the transverse dimensions of the radiation emission window. Moreover, one linear polarization state is stabilized by breaking the cylindrical symmetry of the VCSEL.
Abstract: The present invention relates to a semiconductor laser device and a method for fabrication thereof, wherein the semiconductor laser device exhibits an improved mode selectivity.