Thorlabs' photodetectors are capable of detecting light throughout the UV, VIS, NIR, IR, and THz spectral regions. Our photodetectors feature sensors that enable properties such as intensity, power, intensity distribution, wavefront shape, energy, and wavelength to be measured. We offer unmounted photodiodes as well as amplified, biased, and avalanche photodetectors. Thermal power detectors are available unmounted, mounted on a PCB, or mounted on an aluminum plate. Also available are position-detecting sensors, integrating spheres, single photon detectors, a single photon counting device that counts the pulses from a single photon detector, silicon photomultipliers, photomultiplier modules, THz Antennas, and an acoustic detection module. An intensity noise analyzer, which analyzes an input voltage signal to characterize noise in an optical system by determining the power spectral density (PSD) or relative noise intensity (RIN), is also available. To amplify the output voltage signals from photodetectors, we offer a selection of transimpedance and voltage amplifiers.