Thorlabs offers complete optical spectrum analyzers for FTIR measurements over the near-UV to mid-IR wavelength ranges. Our holographic grating spectrometer is also fiber-compatible and can be easily integrated into an OCT system. The compact CCD spectrometers are fiber compatible and available with 3 different wavelength ranges. The modular Raman spectroscopy kit has options for solid or liquid samples in backscattering or right-angle scattering geometries respectively. Our Fabry-Perot interferometers are ideal for examining fine spectral characteristics of CW lasers. We also provide an acoustic detection module for quartz-enhanced photoacoustic spectroscopy. Our intensity noise analyzer analyzes an input voltage signal from a source such as a photodiode to characterize noise in an optical system by determining the power spectral density (PSD) or relative noise intensity (RIN). We offer integrating spheres that can accept free-space or fiber-coupled sources, have user-configurable ports, and may be calibrated with user-selected sensors upon request.