For more than a quarter century Laser Focus World has kicked off each New Year with a review and forecast of the laser markets. In recent years, the review has been based directly on a survey of laser manufacturers and the resulting articles reflect how these companies view the global market for lasers. Over the years the individual annual predictions have ranged from "gloom and doom" to, what seems in retrospect, the outrageous optimism of last year's forecast that the laser market would grow by 30% during 2001. Regardless of the actual numbers, however, the review does provide the only ongoing objective summary of major trends in our markets and serves as a widely available window into the laser industry. And looking through that window at this year, the numbers for 2001 provide a sobering counterpoint to last year's forecast: the total market estimate for last year has been adjusted down by about half to $5.6 billion. While this adjustment seems enormous, the more significant aspect of this year's survey, I believe, is the projected 10% growth of the industry in 2002a growth that is expected independent of any increase driven by a military buildup (see p. 81). For many, the downturn of 2001 has presented a window of opportunity to rethink their business, refocus on the basics, and be optimistic about the New Year.
Chip for 2.5 Gbit/s combines four functions
Research in short-haul fiberoptics continues with the development of a fully monolithic optoelectronic receiver chip for 850 nm that combines a large-area metal-semiconductor-metal (MSM) diode, a 2.5-Gbit/s transimpedance amplifier (TIA), and a high-gain amplifier. The device, designed and tested by researchers at the Fraunhofer Institut für Angewandte FestkÖrperphysik (Freiburg, Germany) also includes a limiting output buffer that can drive a 50-Ω load. The 300-µm-diameter MSM diode has a capacitance three times lower than a p-i-n device of the same size (paramount to high bandwidth and low noise), but with a higher operation voltage of 10 V. The monolithic integration of the MSM diode with a TIA and a high-gain amplifier eliminates unnecessary inductances, because no wire-bond interconnects are required. The MSM structure was grown on an undoped gallium arsenide substrate before the rest of the structure was deposited. Using an 840-nm vertical-cavity surface-emitting laser as the optical source, the receiver achieved a sensitivity of -15.7 dBm at a bit-error rate of 10-9. On the wafer, the achieved sensitivity was measured to be -17 dBm, claim the researchers. Total power consumption of 500 mW was also reported. Contact Manfred Lang at [email protected].