Genji F Tohmon

US Patent:

20030235227, Dec 25, 2003

Filed:

Jun 19, 2002

Appl. No.:

10/174805

Inventors:

Naresh Chand - Warren NJ, US
Julie Eng - Upper Macungie Township PA, US
Martin Fischer - Bridgewater NJ, US
Philip Kiely - Clinton NJ, US
David Klotzkin - Emmaus PA, US
Keisuke Kojima - Bridgewater NJ, US
Genji Tohmon - Allentown PA, US
Yan Xu - Macungie PA, US

International Classification:

H01S005/00

US Classification:

372/050000

Abstract:

A transmit optical subassembly (TOSA) includes a spot-size-converted (SSC) semiconductor laser coupled to an optical fiber without a lens or isolator. The spot-size-converted semiconductor laser includes an active region and an expander region that expands the spot size of the laser while maintaining efficient active laser performance. The SSC laser is coupled to a submount and passively aligned to an optical fiber positioned within a V-shaped groove formed within the submount. The SSC laser includes a narrow far field advantageous for providing a high coupling efficiency and high quality data transmission. The SSC laser is resistant to back reflection and produces a 1.3 or 1.55 micron optical wavelength and a data rate ranging from 1 to 10 Gbps. The TOSA provides high coupled power due to narrow far field, with potential extra reflection resistance due to absorption and mode transfer losses in coupling reflections through the expander back into the active region. The TOSA meets industry specifications (SDH/SONET) for 15 km transmission and has a maximum optical path penalty of less than 1 dB at a bit error ratio of 10for up to -14 dB back reflection.