Panasonic Develops High-Speed VSCEL

OSAKA, Japan, June 6 -- Panasonic, the brand by which Matsushita Electric Industrial Co. Ltd. is primarily known, announced it has developed a 850-nm AlGaAs/GaAs VCSEL (vertical cavity surface-emitting laser) capable of high-speed 12.5 Gb/s modulation with a low, 8 mA operating current. It said the laser will be used for low-cost optical communication such as plastic fiber communication and spatial light transmission.

To enable high-speed operation of a laser, its parasitic capacitance must be reduced. Panasonic said the new VCSEL uses BCB (benzocyclobutene) resin with a low dielectric constant formed around the light-emitting post structure.

"This structure hugely reduces the parasitic capacitance to less than one third of the conventional value, from 0.7 pF to 0.2 pF," the company said in a statement. "This has doubled the modulation bandwidth previously limited by the parasitic capacitance, realizing the world's highest data transmission rate of 12.5 Gb/s with 12-GHz relaxation oscillation frequency."

It said optimizing the device structure with current confinement via selective oxidation resulted in a low threshold current of 1 mA and a high slope efficiency of 1.1 W/A, and 8 mA for 12.5 Gb/s modulation.

Panasonic said it hopes to begin shipping the two types of surface-emitting lasers (2.5 Gb/s and 12.5 Gb/s) in early 2006, and that it has filed patents for 40 domestic and nine international patents. It presented research and development results at CLEO 2005, held last week in Baltimore.

For more information, visit: panasonic.co.jp/global/index.html