The WS40, a tunable filter that was adapted for 40-Gb/s testing, has been unveiled by Yenista Optics. The component’s FWHM is selectable from 0.3 to 1.0 nm, allowing the user to determine the optimum filtering bandwidth. It has a tuning range of 90 nm over both the C and L bands from 1525 to 1615 nm. Tuning speed between arbitrary wavelengths is typically 40 ms. The PC-based platform of the filter is interfaced through an 8.4-in. touch screen using intuitive software.