Bandwidth Variable Filter of BWTF-series is built based on free-space optics combing with diffraction grating to produce a flat-top transmission. It is a 2-port fibre-optic device. When a wide-band spectrum is injected to the input port, the tuneable filter will select a target band for output and reject the rest band of spectrum. Transmission bandwidth is variable at a centre wavelength fixed within some spectral range. Bandwidth adjustment 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 and polarisation dependent loss (PDL) in the market. Precise tuning mechanism enables filters to provide high wavelength resolution and excellent wavelength-tuning repeatability. Both of manual and electric version filters are available over X-, O-, S-, C-, & L- bands.