Double heterostructure laser for direct coupling to an optical fiber

• US 4,163,953 A
• Filed: 07/07/1977
• Issued: 08/07/1979
• Est. Priority Date: 07/07/1977
• Status: Expired due to Term

• Current Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Springthorpe, Anthony J., Dyment, John C.
• Primary Examiner(s): Davie, James W.
• Application Number:
  US05/813,678
• Time in Patent Office: 761 Days
• Field of Search: 331/94.5 H, 357/17, 357/18
• US Class Current: 372/45.01
• CPC Class Codes: G02B 6/4202 for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: H01S 3/005 Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/026 Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers stabilisation of output H01S5/06
• CPC Class Codes: H01S 5/185 having only horizontal cavities, e.g. horizontal cavity surface-emitting lasers [HCSEL] comprising a photonic bandgap structure H01S5/11
• CPC Class Codes: H01S 5/42 Arrays of surface emitting lasers

Abstract

A double heterostructure laser has a first confining layer on the substrate, an active layer on the first confining layer and a second confining layer on the active layer. A groove is etched through the second confining layer and active layer to form a reflecting surface at approximately 45° to the plane of the active layer. The resonant cavity is formed between a cleaned end surface and a surface at the substrate. A hole through the substrate to the first confining layer is aligned with the reflecting surface for emission therethrough.

Claims

1. A laser having a semiconductor substrate and a double heterostructure on a surface of said substrate, said structure comprising;

a first confining layer of semiconductor material on said surface of said substrate, an active layer of semiconductor material on said first confining layer and a second confining layer on said active layer, said first confining layer being of the same conductivity type as said substrate;

said second confining layer being of the opposite conductivity type as said first confining layer and said active layer being of the same conductivity type as one of said confining layers to form a p-n junction between said active layer and one of said confining layers;

a cleaved end surface on said structure, said end surface extending normal to the plane of said active layer;

a reflecting surface extending through said second confining layer and said active layer and inclined relative to the plane of said active layer to form a resonant cavity between said end surface and a further surface at said substrate surface;

a hole through said substrate to said first confining layer, said hole aligned with said reflecting surface for emission of light therethrough; and

electrical contact means for applying a forward bias to said active layer.

2. A laser as claimed in claim 1, said resonant cavity extending between said end surface of said active layer and the surface of said first confining layer contiguous with said substrate.

3. A laser as claimed in claim 1, said reflecting surface inclined at approximately 45°

to said plane of said active layer.

4. A laser as claimed in claim 1, including a lens structure on said further surface at said substrate surface.

5. A laser as claimed in claim 1, said substrate of GaAs, said active layer and confining layers of GaAlAs.

6. A laser as claimed in claim 1, including a Vee shaped groove etched through said second confining layer and said active layer, and a layer of SiO₂ on one of the surfaces of said V-shaped groove to form said reflecting surface.

7. A laser as claimed in claim 1, including a heat sink layer on said second confining layer.