Welcome to Thorlabs; below you will find links to detectors and instrumentation that measure the various properties of light, a subset of our entire line of photonics products. Thorlabs offers an extensive selection of instruments that measure the properties of light. Our versatile power and energy meters can be used with over 25 different sensors in order to make NIST-traceable power and energy measurements. If the convenience of a meter is not desired, our selection of detectors includes basic photodiodes (uncalibrated and calibrated), photodetectors (biased, amplified, and avalanche), CCD and CMOS arrays, position detectors, integrating spheres, and photomultiplier tubes. The Beam Characterization category contains beam profilers (camera and scanning slit), a wavefront sensor, spectrometers, and interferometers, while the Polarimetery link leads to a selection of instruments used to measure and control the polarization of light.