Title:
LIGHT EMITTING ELEMENT
Document Type and Number:
Japanese Patent JPH02269323
Kind Code:
A
Abstract:
PURPOSE:To obtain an oscillation element which can select oscillatable wavelength at any time, and also, can obtain a signal light of narrow spectral line width in a stable single mode by selecting one of plural pieces of optical waveguides by an optical switch and switching the oscillation wavelength of a semiconductor laser. CONSTITUTION:A signal light 3 emitted from the rear of a semiconductor laser 1 is condensed by a lens 4 and made incident on an optical waveguide 11 on a substrate 5. In this state, optical switches 21, 22 are set suitably so that the signal light 3 is brought to guided wave as it is through the optical waveguide 11 and reaches a diffraction grating 41. In this case, the signal light 3 is reflected by the diffraction grating 41, made incident on the semiconductor laser 1 again, and a laser of an external resonator type is formed by the semiconductor laser 1 and the optical waveguide 11, and the diffraction grating 41. In this state, by selecting suitably the optical switches 21, 22, a signal light 2 of three kinds of different wavelength lambda1 - lambda3 can be obtained. In such a way, by switching the optical waveguides 11 - 13 by the optical switches 21, 22, the oscillation wavelength can be changed at any time, and also, spectral line width of an output can be suppressed to several hundred kHz or less.
Inventors:
YAMAMOTO HIROAKI
MATSUI YASUSHI
MATSUI YASUSHI
Application Number:
JP9134189A
Publication Date:
November 02, 1990
Filing Date:
April 11, 1989
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
G02F1/313; H01S3/063; H01S5/00; H01S5/026; (IPC1-7): G02F1/313; H01S3/18
Attorney, Agent or Firm:
Shigetaka Awano (1 person outside)