US 6,983,000 B2 | ||
Laser diode module | ||
Kimio Tatsuno, Tokyo (Japan); Hiroaki Furuichi, Yokohama (Japan); Kazumi Kawamoto, Yokohama (Japan); and Katsumi Kuroguchi, Yokohama (Japan) | ||
Assigned to Hitachi, Ltd., Tokyo (Japan) | ||
Filed on Jul. 15, 2003, as Appl. No. 10/618,759. | ||
Application 10/618759 is a continuation of application No. 09/934562, filed on Aug. 23, 2001, granted, now 6,597,712. | ||
Claims priority of application No. 2001-050534 (JP), filed on Feb. 26, 2001. | ||
Prior Publication US 2004/0228373 A1, Nov. 18, 2004 | ||
This patent is subject to a terminal disclaimer. | ||
Int. Cl. H01S 3/00 (2006.01); G01J 4/00 (2006.01) |
U.S. Cl. 372—32 | 8 Claims |
1. A laser diode module comprising:
a laser diode device;
a first photo detector part for receiving, directly or indirectly, first divided light that is a first portion of light when
at least one of light emissions of said laser diode device is divided into two portions of light each traveling a different
optical path;
a second photo detector part for receiving second divided light that is a second portion of light thus divided via at least
a wavelength selective member; and
means for controlling the lasing wavelength of said laser diode device on the basis of outputs of said first and second photo
detector parts;
wherein a beam splitter is provided between said laser diode and said wavelength selective member for dividing light emitted
from said laser diode into the first and second divided light; and
wherein at least a quarter-wave plate is provided in an optical path between said beam splitter and said wavelength selective
member.
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