Nils Otterstrom, Brigham Young University
Physical Sciences
Filtered photodiodes show potential as inexpensive laser wavelength meter. Photocurrents are measured digitally. The photocurrent is digitized using externally controlled integration times to achieve the highest precision possible from the digital to analog converters on the photosensor chip. Using an algorithm we’ve developed and calibrated intensity curves, we can precisely calculate wavelength from the output of the different photodiodes. Limitations due to etaloning from reflections off of the surfaces of the filters were analyzed and effectively mitigated, allowing the device to achieve high precision with a stability of 0.102 nm over several hours.