Photodigm claims breakthrough in surface-emitting lasers, secures $1 million government contract
Optical components supplier Photodigm Inc. has achieved a breakthrough in 1310-nm Grating-outcoupled Surface Emitting (GSE) laser technology, say company representatives, yielding devices with singlemode output powers up to 6mW--essentially providing the performance of a DFB laser with the advantages of a VCSEL.
Until now, 1310-nm lasers have been available only as edge-emitting lasers. While the industry has devoted huge resources towards the development of surface emitting 1310-nm VCSELs, the results have been generally unsuccessful due to the inherent difficulties of developing and qualifying a new material structure, contends the company. Photodigm's GSE laser uses an edge-emitting epitaxial material structure (AlInGaAs/InP) and relies on first and second order gratings for the DBR reflectors and the outcoupler.
"This represents a significant breakthrough for Photodigm," explains John Spencer, president and chief executive officer. "For the first time we have shown that a small outcoupler grating can deliver a significant amount of power into singlemode fiber. With this unique semiconductor laser architecture, we expect to provide major improvements in the cost and performance of a wide range of photonic devices in the enterprise and access markets."
Photodigm's devices exhibit singlemode operation with output powers up to 6 mW, threshold currents below 20 mA, slope efficiencies of 0.1 mW/mA, 5 deg x 7 deg beam divergence, modulation speeds of 2.5 Gbits/sec and SMSR greater than 35 dB. Its narrow beam divergence provides improved fiber coupling capability and, because it is a surface-emitting device, it offers significant efficiencies in testing and packaging.
In a separate development, Photodigm has been awarded a contract for approximately $1 million from the U.S. Government to develop a high power surface-emitting laser. This program builds on Photodigm's GSE laser technology by including a lens-like lateral layer for mode control. The resulting lens-like grating-outcoupled surface-emitting (LLGSE) laser is designed to produce a "high brightness" beam with a 975-nm wavelength and output power up to 10 Watts.
For more information about Photodigm Inc. (Richardson, TX), visit the company's Web site at www.photodigm.com.