November 3, 2006, Wheeling, IL and Santa Rosa, CA--Two small light emitters produced by separate companies are very different in approach and serve different purposes.
LED
One, produced by Opto Technology, which makes optoelectronic and LED-related products for the biomedical and analytical-instrumentation industry, is a broadband white-LED light engine (the OTLA-0130). But, in fact, it is not just a white-light LED; it integrates a white LED with four narrowband LEDs emitting at 395, 470, 630, and 660 nm in a small package. The emitting source size is less than 2 mm in diameter, allowing the emitter to be coupled to optical systems including fiber optics and focusing optics. In addition, each LED can be individually addressed for separate pulsing and intensity balancing. Electrical termination is through an industry-standard edge connector or by soldering wires directly to the circuit board.
Potential instrumentation applications include fluorescence, absorbance, transmittance, reflectance, and color-metric measurements. The emitter may be customized to fit specific applications--for example, by fitting additional LED wavelengths into the existing package.
Blackbody
The other, made by Cal Sensors, is a low-cost broadband blackbody emitter in a TO-5 package; the emitter provides higher output compared to standard steady-state emitters of blackbody radiation (blackbody emitters are important for calibrating many optical setups). The radiating element in the steady-state emitter is a coiled filament of a proprietary material with a specialized coating that gives it an emissivity of 0.70. The filament, and a new generation of reflectors, boost output efficiency. The radiated output closely emulates a blackbody in spectral distribution. The emitter is designed to operate at a rated filament temperature of 1170 K. The emitters range in input power from 1.15 to 2.1 W. The packages are windowless, providing long-term stability and lifetime without spectral attenuation caused by window materials.