Wavelength-tunable variable fiber-optic attenuator using liquid-crystal-mirror hybrid controls

Fiber-optic module is proposed using a hybrid liquid-crystal (LC)-mirror mechanics beam control mechanism that provides the dual functions of optical attenuation controls and wavelength selection with a high degree of sensitivity, all within one compact in-line module. The experimental module uses an LC deflector and a mechanically tuned bulk mirror as the hybrid optics. The module demonstrates a 1520-1570-nm coarse tuning range, a 1.44-nm fine tuning range, a >30-dB attenuation range, a 3.7-dB optical insertion loss,<0.1-dB polarization- dependent loss, and a full-width at half-maximum wavelength resolution of ≤0.3 nm. Module applications include tunable gain controlled optical transmitters and receivers.