Technical Insight
Cielo Demonstrates 2.5 Gb/s SONET Link Using 1.3 m VCSELs (Fiber Optics News)
Cielo Communications (Broomfield, CO) has demonstrated OC-48 (2.5 Gb/s) error-free data transmission over 20 km of single-mode fiber using a 1.3 m VCSEL. Developed jointly with Sandia National Laboratories [see CS 6(5), p. 67], the short reach transmitter was tested for SONET compliance and achieved a bit error rate (BER) of < than 10-12. The transceiver link consisted of a packaged VCSEL transmitter and laser driver, and a PIN photodiode receiver with transimpedance- and post-amplifiers, in addition to commercially available ICs and proprietary optical packaging. Long wavelength VCSELs are being sought for telecommunication optical transmitters because of the advantages offered over existing edge-emitting lasers, which include faster modulation speeds, easier testing capability, smaller size, lower power consumption and device costs. "Based on the its inherent technical advantages, the 1.3 m VCSEL will obsolete the majority of 1.3 m edge-emitting lasers used in telecommunications today," claims Bob Mayer, Cielo s VP of marketing. "Our achievement is a major milestone in demonstrating the capability of the 1.3 m VCSEL to deliver the performance required in SONET applications. The optical power, wavelength and spectral purity have been the major hurdles for 1.3 m VCSEL technology, and we are excited about our optical transmitter since it exceeds these OC-48 short reach requirements with considerable margin."
