Optical devices having ZNS/CA-MG-fluoride multi-layered mirrors
AssigneeLucent Technologies Inc.
InventorsLeo Maria Chirovsky, Sanghee Park Hui, George John Zydzik
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Abstract
In a multi-layered dielectric mirror the higher refractive index layers comprise ZnS and the lower refractive index layers comprise a composite of approximately 95%MgF2 and 5%CaF2 by mole fraction. In one embodiment, the fluoride layers are e-beam deposited from an essentially eutectic melt of the two fluorides. In another embodiment, the semiconductor surface on which the mirror is formed is protected by an aluminum borosilicate glass layer. Application of the invention to the design and fabrication of VCSELs is also described.
Claims22
An optical device comprising
- a multi-layered dielectric mirror for reflecting radiation at a center wavelength,
- said mirror including a plurality of pairs of essentially quarter-wavelength thick dielectric layers, each pair comprising a relatively high refractive index layer and a lower refractive index layer, characterized in that
- said high refractive index layer comprises ZnS, and
- said lower refractive index layer comprises a composite of CaF2 and MgF2, and
- said device includes a semiconductor surface and a glass layer disposed on said surface, said mirror being disposed on said glass layer.
A laser for generating radiation at a center wavelength comprising
- a cavity resonator formed by at least a first multi-layered mirror, said first mirror including a plurality of pairs of essentially quarter-wavelength thick dielectric layers, each pair comprising a relatively high refractive index layer and a lower refractive index layer, and
- an active medium disposed within said resonator for generating said radiation when suitably pumped, characterized in that
- said high refractive index layer comprises ZnS, and
- said lower refractive index layer comprises a composite of approximately 95% MgF2 and 5% CaF glass by mole fraction.
A VCSEL for generating radiation at a center wavelength comprising
- a pair of multi-layered mirrors forming a cavity resonator having a resonator axis perpendicular to said layers, each of said mirrors comprising a plurality of pairs of essentially quarter-wavelength thick layers, each pair comprising a relatively high refractive index layer and a lower refractive index layer, and in at least one of said mirrors said high refractive index layers comprise ZnS and said lower refractive index layers comprise a composite of approximately 95% MgF2 and 5%CaF glass by mole fraction,
- an active region disposed within said resonator for generating said radiation when suitably pumped, and
- current guide means for directing pump current through a current aperture to said active region to generate said radiation which propagates along said axis, a portion of said radiation forming an output signal which emerges through at least one of said mirrors.
A method of fabricating a multi-layered dielectric mirror for reflecting radiation at a center wavelength comprising the steps of
- depositing a plurality of pairs of essentially quarter-wavelength thick layers on a substrate, each pair comprising a relatively high refractive index layer and a lower refractive index layer, characterized in that
- said high refractive index layers are deposited as ZnS, and
- said lower refractive index layers are deposited by e-beam evaporation as a composite of approximately 95% MgF2 and 5% CaF2 by mole fraction from a source which comprises a eutectic melt of approximately 53% MgF glass and 47% CaF2 by mole fraction.
Dependencies are inferred from the claim text.