# US 5,349,604 A · Semiconductor laser source

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- Number: US 5,349,604 A
- Document ID: US5349604A
- Status: Granted
- Kind: A
- Application number: 08/030,863
- Filed: 1993-03-12
- Granted: 1994-09-20
- Earliest claimed: 1992-03-13
- Assignees: Rohm Co., Ltd.
- Inventors: Naotaro Nakata
- Web page: https://patentgrep.com/patent/US5349604A

## CPC

- G02B 6/4204: {the coupling comprising intermediate optical elements, e.g. lenses, holograms (encapsulated active devices H01S5/02208)}
- 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)}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL

## Abstract

A laser diode and a lens are fixed onto a laser fixing member. A laser beam emitted from the laser diode passes through the lens, and a part of the laser beam passes through a pinhole provided to a beam restricting plate. The pinhole is formed so that its diameter is smaller than the laser beam diameter at the beam restricting plate. The laser beam is transmitted therethrough while being diffracted.

## Claims

### Claim 1

A semiconductor laser source comprising:
beam emitting means including a semiconductor laser for emitting a laser beam;
an optical system transmitting and collimating the laser beam emitted from said beam emitting means; and
a beam restricting member provided with an aperture of a size which is predetermined so that a central portion of the laser beam from said optical system is transmitted and diffracted while a remaining nonuniform portion of the laser beam is removed.

### Claim 2 (depends on 1)

A semiconductor laser source according to claim 1, wherein said beam emitting means comprises a laser diode provided with a laser chip for emitting one laser beam.

### Claim 3 (depends on 1)

A semiconductor laser source according to claim 1, wherein said optical system comprises a lens for transmitting the laser beam emitted by the beam emitting means.

### Claim 4 (depends on 1)

A semiconductor laser source according to claim 1, wherein said beam restricting member comprises a beam restricting plate of a thin plate form provided with a circular pinhole.

### Claim 5 (depends on 1)

A semiconductor laser source according to claim 1, wherein said aperture is smaller than a laser beam diameter at the beam restricting member.

### Claim 6 (depends on 1)

A semiconductor laser source according to claim 1, wherein a center of said aperture coincides with a center of the laser beam at the beam restricting member.

### Claim 7

A semiconductor laser source comprising:
beam emitting means including a semiconductor laser for emitting a laser beam;
an optical system transmitting and collimating the laser beam emitted from said beam emitting means;
a fixing member fixing said beam emitting means and said optical system; and
a beam restricting member provided with an aperture of a size which is predetermined so that a central portion of the laser beam from the optical system is transmitted and diffracted while the other nonuniform portion of the laser beam is removed.

### Claim 8 (depends on 7)

A semiconductor laser source according to claim 7, wherein said beam emitting means comprises a laser diode provided with a laser chip for emitting one laser beam.

### Claim 9 (depends on 7)

A semiconductor laser source according to claim 7, wherein said optical system comprises a lens for transmitting the laser beam emitted by the beam emitting means.

### Claim 10 (depends on 7)

A semiconductor laser source according to claim 7, wherein said fixing member has a through hole and said beam emitting means and said optical system are inserted into the hole.

### Claim 11 (depends on 10)

A semiconductor laser source according to claim 10, wherein said beam emitting means is a laser diode which is fixed in a condition where its head is inserted into the hole, and wherein said optical system is a lens which is fixed inside the hole in a condition where it is fixed inside a lens barrel.

### Claim 12 (depends on 7)

A semiconductor laser source according to claim 7, wherein said beam restricting member comprises a beam restricting plate of a thin plate form provided with a circular pinhole.

### Claim 13 (depends on 7)

A semiconductor laser source according to claim 7, wherein said beam restricting member is fixed to said fixing member.

### Claim 14 (depends on 7)

A semiconductor laser source according to claim 7, wherein said aperture is smaller than a laser beam diameter at the beam restricting member.