A Low Cost Compact Laser Wavelength Sensing Device
The need for an inexpensive, compact device that can replace the function of a spectrometer led to this project. A previously fabricated Graded Wavelength Reflection Filter (GWRF) photonic crystal was used to measure the wavelengths of an infrared tunable diode laser beam. The device was illuminated completely with the beam, which was expanded using a lens. A charge-coupled device (CCD) was placed behind the GWRF, parallel to it. The laser's wavelength was tuned in the 859.5 - 868 nm range. Data was saved every 0.5 nm and plots of Detected Intensity vs. CCD Pixel Location were obtained. In cases where the laser's wavelength matched a wavelength in the GWRF a dark spot was observed in the CCD. As a result, an intensity minimum was obtained in the plot. The shifting of the intensity minimum due to a change in the wavelength of the laser beam was observed. This device is expected to serve many sensing applications at a low cost.
School:
University of Puerto Rico at Mayagüez
Department:
Chemical Engineering
Research Advisor:
Brian Cunningham
Department of Research Advisor:
Electrical and Computer Engineering
Year of Publication:
2006