Resonant optothermal detector for use as an optical power meter

We present a method of optical power measurement which can be used to measure optical radiation over a large part of the optical spectrum without switching between different sensor types. Based on resonant optothermal detection using a miniature quartz tuning fork, we find that the use of this method has superior dynamic range in the measurement of optical power. With use of the pyroelectric effect, sensitivities are comparable to standard pyroelectric detectors and measurement of quasi-CW modulated optical signals is a simple task. An optical power meter which uses this method can be put to use as a compact and low cost device in a wide variety of applications.