Before tunable lasers, network operators had to use expensive, bulky fixed-wavelength lasers, a burden at all levels of the supply chain. Optical communications corporation JDSU (Milpitas, CA) has demonstrated a photonic integrated circuit (PIC) that incorporates a widely tunable laser and a Mach-Zehnder modulator onto a single chip. Small enough to fit on the tip of a finger, the transmitter chip is intended for dense wavelength-division-multiplexing communications systems at infrared wavelengths between 1528 and 1568 nm.
When packaged, the chip will be capable of producing +5 dBm of modulated power in an optical fiber while consuming less than 1.5 W of power over a temperature range of -5°C to 70°C. The transponders and transceivers that use the chip will be able to accommodate dispersion-limited transmission over distances of up to 100 km at rates greater than 11.3 Gbit/s, scalable to 40 Gbit/s. Measuring only 4 mm long, the chip enables communications systems to use significantly smaller transceivers, such as the 300-pin small-form-factor and pluggable small-form-factor devices. The company expects to have products containing the PIC available in 2008. Contact Greg Fish at [email protected]. (Photo courtesy of JDSU)