公开(公告)号：JPH09191151A

公开(公告)日：1997-07-22

申请号：JP34074396

申请日：1996-12-20

Applicant: LUCENT TECHNOLOGIES INC

Inventor： DAUTREMONT-SMITH WILLIAM ,  HAYES TODD ROBERT

IPC: H01S5/12 ,  H01S5/20 ,  H01S5/227 ,  H01S3/18

Abstract: PROBLEM TO BE SOLVED: To provide a distributed feedback layer which is less in hole burning and chirping. SOLUTION: An epitaxial layer 20 is formed on the main surface of a semiconductor substrate 10 and a pair of silicon dioxide masks 31 and 32 is formed on the substrate 10 so that a fixed interval can be maintained between the masks 31 and 32. The widths of the masks 31 and 32 spatially change. It is effective when the epitaxial layer 20 has a refractive index which is different from that of the substrate 10 at the operating wavelength of a laser. Then the masks 31 and 32 are removed and the layer 20 is etched into stripes. The height of the diffraction grating stripes thus obtained spatially changes along the Y-direction expansion of the masks 31 and 32 and the coupling between the diffractive grating and an active layer also changes similarly. Therefore, a high-performance semiconductor laser can be manufactured by adjusting the light output of the laser.

公开(公告)号：DE60133960D1

公开(公告)日：2008-06-26

申请号：DE60133960

申请日：2001-02-19

Applicant: LUCENT TECHNOLOGIES INC

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

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

Abstract: A fiber Raman amplifier is configured to use a co-propagating Raman pump source, which may be beneficial in a variety of system configurations (for example, in bidirectional communication systems). By carefully configuring the pump source characteristics, sufficient optical gain can be achieved in the co-propagating arrangement, the characteristics including: (1) using an optical pump power of at least 50mW, (2) having a relatively large spectral bandwidth within the pump (to suppress SBS); and (3) a frequency difference between all longitudinal pump modes of each pump laser being separated by at least the walk-off frequency between the pump laser frequency and the signal frequency, and all intense longitudinal modes between different pump lasers being separated by at least the electrical bandwidth of the communication system.