High spectral range, high speed fiber optic spectrometer

Fiber optic sensors have been developed recently. Among them, some encompass high speed and the others broadband spectral response. Newly, high-speed fiber-optic spectrometer (HSFOS) has been investigated. Operation of this type of spectrometer is based on conversion of spectral-domain signal into time-domain by a dispersive element. In spite of the high speed, the HSFOS supports only a narrow frequency band of the incoming light. In this paper, we used adequate photonic crystal fiber (PCF) as dispersive fiber in forming the measured spectrum from a nano-cavity sensor in order to improve the HSFOS spectral range. Spectral range enhancement of the spectrometer by means of PCF was also studied. Simulation results show that the increment of spectral range decreases the speed of spectrometer; therefore a trade-off between spectral range and speed is studied.