Bristol Instruments flagship products include interferometer-based wavelength meters and spectrum analyzers that accurately characterize the wavelength and spectral properties of CW and pulsed lasers that operate from the visible to the mid-IR. The wavelength of WDM lasers and WDM signals can also be measured with a family of optical wavelength meters and multi-wavelength meters. In addition, an optical thickness gauge is offered for non-contact thickness measurement of a variety of materials.