Optically Tunable Photonic Bandgap Fiber

Transmission spectrum of the dyedoped nematic liquid crystal photonic bandgap fiber, which absorbs light with wavelengths between 450 nm and 600 nm. (a) Inset shows an optical micrograph of the PCF end facet. Simulated mode profile of a shortwavelength cladding mode propagating in the LC (b) and guided mode in the core (c). The dynamic response is measured by placing a continuouswave probe laser on a PBG edge and pumping the LC with a square-wave modulated 532 nm pump laser with a power of 2-3 mW. The probe rise and decay time was 250 μs and 120 μs, respectively, in response to a 500 μs pump pulse (d). Wavelength [nm] Tr an sm is si on [d B ] 0