Narrowband Tunable Optical Filter of WLTF- NM (or -NE) -series is built based on free-spaceoptics combing with diffraction grating to produce a Gaussian-shape transmission. It is a 2-port fiber-optic device. When a wide-band spectrum is injected to the input port, the tunable filter will select a target band for output and reject the rest band of spectrum. Wavelengthtuning is actuated by either a precise micrometer driver or a micro step-motor connected to a PC
through a USB interface in which actuation is monitored by a built-in encoder and controlled dynamically in a closed-loop. Patent-pending optics design offers a great option of bandwidths and tuning ranges with unprecedented low insertion loss andpolarization dependent loss (PDL) in the market. Precise tuning mechanism enables filters toprovide high wavelength resolution and excellent wavelength-tuning repeatability. Both of manual and electric version filters are available over X-, O-, S-, C-, & L- bands.