EP0243170A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Semiconductor laser apparatus

Assignee: Sony Corp

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Filing: 1987-04-22

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Granted: —

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Expires: 2007-04-22

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Abstract

Abstract A semiconductor laser apparatus has a semiconductor laser diode (21) for radiating a laser beam (30a), a photodetector (23) formed on a semiconductor substrate (22), a prism (24) having a first plane (24a) for introducing the laser beam (30a), for example onto an optical disc, and for introducing a reflected laser beam (30r) from the optical disc onto the photodetector (23); and a second plane (24b) facing the photodetector (23), and a coating layer (27, 28) formed on the boundary between the semiconductor substrate (22) and the prism (24). The coating layer (27, 28) has a refractive index such that laser light (30s) incident from the first plane (24a) other than the reflected laser beam (30r) is inhibited from reaching the photodetector (23).

Inventors

👤 You Yoshitoshi
👤 Yoshiyuki Matsumoto

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-11-03 15:46

CPC Classifications

G; G02; G02B; G02B1/00; G02B1/10; G11; G11B; G11B7/00; G11B7/12; G11B7/123; G11B7/135; G11B7/1359; G11B7/1381; H; H01; H01S; H01S5/00; H01S5/02; H01S5/022; H01S5/0225; H01S5/02255; H01S5/023; H01S5/02325; H01S5/06; H01S5/068; H01S5/0683

Claims Analysis

Total Claims: 6

Claim 1

Independent Claim 124 words

A semiconductor laser apparatus comprising: a semiconductor substrate (22); and a semiconductor laser diode (21) for radiating a laser beam (30a); characterized by: a photodetector (23) formed on said semiconductor substrate (22); a prism (24) having a first plane for introducing said laser beam (30a) to a reflecting substance and introducing a laser beam (30r) reflected by said reflecting substance to said photodetector (23) and a second plane (24b) facing said photodetector (23); and a coating means (27, 28) formed on a boundary between said semiconductor substrate (22) and said prism (24), having a refractive index such that laser light incident from said first plane (24a) other than said laser beam (30r) reflected by said reflecting substance is inhibited from reaching said photodetector (23).

Claim 2

Dependent Claim 124 words

Claim 3

Dependent Claim 28 words

Apparatus according to claim 1 wherein said coating means (27, 28) is formed of a plurality of layers (27, 28), each of which has a different refractive index.

Claim 4

Dependent Claim 31 words

Apparatus according to claim 2 wherein said plurality of layers (27, 28) consists of two layers (27, 28), a first layer (27) of SiO₂ and a second layer (28) of Si₃N₄.

Claim 5

Dependent Claim 24 words

Apparatus according to claim 3 wherein said first layer (27) is thicker than said second layer (28) and formed on said semiconductor substrate (22).

Claim 6

Dependent Claim 22 words

Apparatus according to claim 1 wherein said first plane (24a) and said second plane (24b) of said prism (24) are respective half-mirrors.

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