Technical Insight
Laser suppliers tune up to standardization (Fiber Optics News)
A number of tunable laser suppliers have been hitting the headlines recently, announcing new products, receiving large funding rounds or promoting the development of standards for tunable products. However, all tunable technologies are not the same. While companies such as Agility and ADC (which purchased the Swedish company Altitun) have developed single-chip solutions, other manufacturers New Focus, Iolon and Blue Sky Research, all based in San Jose, CA have introduced products based on external cavity designs. In this approach, a standard laser chip is placed within a cavity that can be adjusted in order to tune the output wavelength of the device. Iolon has received a total of $69 million in funding during the last eight months to develop and ramp up production of its first widely tunable laser product. Tuning is achieved by a movable mirror that directs light onto different parts of a diffraction grating the mirror is turned using a small actuator manufactured in MEMS technology. The company claims the device can deliver 20 mW of power, and that it is tunable across a 40 nm wavelength range. Blue Sky Research has used a different approach its external cavity does not use mechanical tuning. Instead the device has a micro-etalon wavelength locker that is controlled electronically, providing switching speeds in the microsecond picosecond range. The device employs relatively low-cost Fabry Perot laser diodes (which are obtained from external sources) and allows narrowband tuning to channel spacings of 50 GHz, with a 25 GHz product in development. New Focus also claims 20 mW output power for its PowerTune module, which integrates a high-power laser, a wavelength locker, power control and other control functions and covers the entire C-band (15281563 nm). In contrast with the 20 mW products from Iolon and New Focus, Agility s tunable sampled grating DBR laser has an output power of 4 mW. The device has four sections including two DBR gratings: tuning is provided by varying the current to these sections (see ). The path to standardization Several efforts are under way to develop standards that will enable customers to design their systems more easily around common tunable laser interfaces. After reports emerged that Agility, Iolon and New Focus had held discussions with the Optical Internetworking Forum (OIF), ADC and Agility announced an initiative to promote the tunable laser industry s initial standards for a 40-pin parallel form factor, electronic interfaces and host-level software commands. "We believe this initiative will greatly benefit all customers who have a demand for tunable lasers," said Rob Plastow, chief technology officer of ADC s fiber-optics division. "In an evolving marketplace, the ability to provide compatible products with similar interfaces will speed network deployment, while ensuring product quality and reliability."
