Articles

All-fiber Polarimetric Electric Field Sensing Using Liquid Crystal Infiltrated Photonic Crystal Fiber.

Sunish Mathews et al. — Wed, 18 May 2011 07:14:46 PDT

The operation of an all-fiber polarimetric electric field sensor based on nematic liquid crystal infiltrated photonic crystal fiber is demonstrated. A section less than 1 mm long of a selectively infiltrated polarization maintaining photonic crystal fiber is used as the probe. The transmission properties are studied for different lengths of the infiltrated section of the fiber subjected to an electric field. It is shown that the phase birefringence of the fiber can be controlled by adjusting the length of the infiltrated section subjected to an electric field, which allows for the sensor to have a linear transmittance response with the applied electric field intensity. The sensor is operated in the telecommunication window at 1550 nm and can be used for the fabrication of all-fiber electric field sensors for high and low electric field environments with an appropriate choice of liquid crystal material for infiltration and with optimization of the infiltration length.

Directional Electric Field Sensitivity of a Liquid Crystal Infiltrated Photonic Crystal Fiber.

Sunish Mathews et al. — Wed, 18 May 2011 07:14:44 PDT

The directional sensitivity of nematic liquid crystal infiltrated polarization-maintaining photonic crystal fiber to an externally applied electric field is evaluated for two-dimensional electric field sensing. Selectively infiltrated and infiltration length optimized polarization-maintaining photonic crystal fiber is used as a probe. Using a polarimetric scheme, the polarized transmission properties of the infiltrated fiber are evaluated in terms of the orientation of the fiber polarization axis in an electric field. It is shown that the sensor has varying sensitivity to electric fields oriented at different angles with respect to the fiber polarization axis. The proposed low-cost all-fiber sensor can be used for two-dimensional directional electric field sensing.

Liquid Crystal infiltrated Photonic Crystal Fiber for Electric Field Intensity Measurements.

Sunish Mathews et al. — Wed, 18 May 2011 07:14:41 PDT

The application of nematic liquid crystal infiltrated photonic crystal fiber as a sensor for electric field intensity measurement is demonstrated. The device is based on an intrinsic sensing mechanism for electric fields. The sensor probe, which consists of a 1 cm infiltrated section of photonic crystal fiber with a lateral size of ∼125 μm, is very compact with small size and weight. A simple all-fiber design for the sensor is employed in an intensity based measurement scheme. The transmitted and reflected power
response of the infiltrated photonic crystal fiber is shown to have a linear response with the applied electric field. The sensor is operated in the telecommunication window at 1550 nm. The temperature dependence of the device at this operating wavelength is also experimentally studied and discussed. These structures can be used to accurately measure electric field intensity and can be used for the fabrication of all-fiber sensors for high electric field environments as both an in-line and reflective type point sensor.

All-fibre Temperature Sensor Based on Macro-bend Singlemode Fibre Loop

Ginu Rajan et al. — Fri, 17 Oct 2008 08:59:53 PDT

An all-fibre temperature sensor is proposed based on a macro-bend singlemode fibre loop using a ratiometric power measurement scheme. The sensor has a linear characteristic with temperature at a fixed wavelength and bend radius. A direct linear relationship between the bend loss of the singlemode fibre and temperature is reported for the first time. By measuring the change in bend loss of the system a change in temperature can be measured assuming the system is calibrated. The proposed sensor has a higher temperature resolution than other conventional fibre-optic sensors and also benefits from simplicity.