Title:
ANALYZER OF LIGHT SPECTRUM
Document Type and Number:
Japanese Patent JPH05256702
Kind Code:
A
Abstract:
PURPOSE:To measure the spectrum of high output power from an optical fiber with good accuracy by inserting an optical attenuator plate between a concave mirror and a diffraction grating. CONSTITUTION:When the light enters via an optical fiber 1 from an optical connector provided at an optical input part, the light is changed to a parallel light beam by a collimator mirror 2. Thereafter, the light is attenuated to the suitable level by a continuously variable attenuator plate 8 and a stepped variable attenuator plate 9. The light is then diffracted corresponding to the wavelength by a diffraction grating 3, reflected by a plane mirror 4 and a condenser mirror 5 to enter a photodetecting sensor 7 through a slit 6. The plates 8, 9 are inclined to the optical axis and formed in a chevron-like configuration. Accordingly, the shift of the luminous fluxes due to the refraction at the plates 8, 9 is offset, and the optical systems in front of and in the rear of the plates 8, 9 can be aligned separately. The photodetector circuit is prevented from being saturated, so that the spectrum of the measuring light of the decreased input level is obtained while the shape of the original spectrum of the transmitted light is maintained.
Inventors:
Kazuo Shigeno
Application Number:
JP8995392A
Publication Date:
October 05, 1993
Filing Date:
March 13, 1992
Export Citation:
Assignee:
NEC
International Classes:
G01J3/18; G01J3/30; (IPC1-7): G01J3/30; G01J3/18
Attorney, Agent or Firm:
Yusuke Omi