The leading manufacturers of Fiber optic attenuators are listed below. Narrow down on the list of companies based on their location and capabilities. Suitable for Internet of Things (IoT), computing. Thorlabs has a wide variety of single mode (SM), polarization-maintaining (PM), or multimode (MM) fixed and variable optical attenuators (VOAs). We offer SM and PM electronic VOAs that provide control of the output power with FC/PC or FC/APC connectors. Pasternack Enterprises started in 1972 in Irvine, California as a manufacturer of log amplifiers.