BROOMFIELD, Colo., Dec. 11 -- By making a full transceiver link with a 1.3µm vertical-cavity surface-emitting laser (VCSEL) and transmitting error-free data over 20 km of single-mode fiber, Cielo Communications contends that low-cost, power-efficient and high-density SONET-compliant optical systems are a possibility. The SONET-compliant OC-48 short-reach optical transmitter was constructed with a 1.3 µm VCSEL and commercially available integrated circuits and proprietary optical packaging, the company said. Based on the VCSEL's inherent technical advantages, the 1.3 µm VCSEL will obsolete the majority of 1.3 micron edge-emitting lasers used in telecommunications today, said Bob Mayer, the company's vice president of marketing. Our achievement is a major milestone in demonstrating the capability of the 1.3 micron VCSEL to deliver the performance required in SONET applications. The optical power, wavelength and spectral purity have been the major hurdles for 1.3 micron VCSEL technology; we are excited about our optical transmitter, since it exceeds these OC-48 SR requirements with considerable margin. The OC-48 optical link was constructed and tested for compliance with the SONET standard at Cielo's Colorado facility. The bit error rate for the link was better than 1E-12, the company said. The VCSEL was developed in conjunction with Sandia National Laboratories. Cielo Communications develops VCSEL technology and optical packaging.