公开(公告)号：JP2001311973A

公开(公告)日：2001-11-09

申请号：JP2001056619

申请日：2001-03-01

Applicant: LUCENT TECHNOLOGIES INC

Inventor： ACKERMAN DAVID ALAN ,  BACHER KENNETH L ,  DAUTREMONT-SMITH WILLIAM C ,  DU MEI ,  ROTTWITT KARSTEN ,  STENTZ ANDREW J ,  STRASSER THOMAS ANDREW ,  ZHANG LIMING

IPC: G02F1/35 ,  H01S3/06 ,  H01S3/30 ,  H04B10/00 ,  H04B10/17

Abstract: PROBLEM TO BE SOLVED: To provide a co-propagating Raman amplifying system which provides a sufficient on-off gain without causing pump signal crosstalk and signal pump signal crosstalk at unwanted level, and makes the device useful. SOLUTION: A fiber Raman amplifier is configured to use a co-propagating Raman pumping source, and this is advantageous in various system configurations. One example is a bi-directional communication system. A sufficient optical gain can be obtained with the co-propagating system by carefully configuring pumping source characteristics. These characteristics include the points such as (1) to use at least 50mW optical pump power, (2) to have a relatively large spectrum bandwidth in the pump for suppressing SBS, (3) a frequency difference among all the vertical pump modes of each pump laser is separated by at least a walk-off frequency between a pump laser frequency and a signal frequency, and all the strong vertical modes among individual pump laser are separated by at least an electric frequency bandwidth of a communication system.

公开(公告)号：JPH10229247A

公开(公告)日：1998-08-25

申请号：JP32353897

申请日：1997-11-25

Applicant: LUCENT TECHNOLOGIES INC

Inventor： CHAKRABARTI UTPAL KUMAR ,  DAUTREMONT-SMITH WILLIAM C ,  WANG KOU-WEI ,  WILT DANIEL PAUL

IPC: H01S5/00 ,  G02B1/00 ,  G02B1/10 ,  H01L31/0216 ,  H01L33/44 ,  H01S5/028 ,  H01S3/18

Abstract: PROBLEM TO BE SOLVED: To lower the reflectance sensitivity of the low-reflectance(LR) coating film of a semiconductor laser with respect to the thickness fluctuation of the coat film. SOLUTION: An LR coat film 14 is formed in a single layer, composed of yttrium and an aluminum oxide(YAO). The coat film 14 is formed on an output facet, formed of the end faces of a plurality of InP clad layers and an InGaAsP layer 9 (having an effective refractive index of about 3.2) which constitute an active region 20 of a laser 10 by vapor-depositing a raw material, composed of yttrium aluminum garnet with an electron beam. The thickness tqw of the coat film 14 is adjusted to about tqw =mλ/4nc (where, m, nc , and λrespectively represent an odd number, the refractive index of the coat film, and the operating wavelength of the laser 10). Therefore, the manufacturing yield of an optical device is improved, because the reflectance of the coat film merely changes moderately, as compared with that of the conventional coat film, even when the actual thickness of the coat film is more or less deviated from the tqw .