We demonstrate electrically and mechanically induced long period gratings (LPGs) in a photonic crystal fiber (PCF) filled with a high-index liquid crystal. The presence of the liquid crystal changes the guiding properties of the fiber from an index guiding fiber to a photonic bandgap guiding fiber - a so called liquid crystal photonic bandgap (LCPBG) fiber. Both the strength and resonance wavelength of the gratings are highly tunable. By adjusting the amplitude of the applied electric field, the grating strength can be tuned and by changing the temperature, the resonance wavelength can be tuned as well. Numerical calculations of the higher order modes of the fiber cladding are presented, allowing the resonance wavelengths to be calculated. A high polarization dependent loss of the induced gratings is also observed.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.
"Since the attributes of LCs can be tuned easily by applying external stimuli, the transmission characteristics of PLCFs can be simply manipulated in thermal2345678910111213, electric [2,4,9,11,1415161718192021, or optical [3,19,21,22] fields. PLCFs have great potential for practical applications, including long-period gratings [16,22], polarimeters , and filters . Mach et al. demonstrated thermal control of the transmission power of a microstructure optical fiber . "
[Show abstract][Hide abstract]ABSTRACT: This work demonstrates a multi-stable variable optical attenuator (VOA) that is fabricated by infiltrating a photonic crystal fiber (PCF) with a liquid crystal (LC) gel. Varying the cooling rate or biasing the electric field during gelation yields various degrees of scattering. Therefore, LC gel-filled PCFs with various transmittances can be realized. At a wavelength of 1550 nm, an attenuation rate of −33.4 dB/cm is obtained at a cooling rate of 30°C/min and a biasing voltage of 400 V during gelation. The proposed all-in-fiber VOA exhibits tunable attenuation and multiple stable states at room temperature.
"A lot of researches have been made to study the production of sensor based on PCF filled with fluid. Birefringence tunable optical devices based on sleeve type of PCF selective filling polymer were researched by Noordegraaf et al. . In document , it introduced that the continuous tuning birefringence was realized by applied transverse voltage on the PCF filled by liquid crystal. "
"The introduction of the LC or RIF provides additional degree of freedom for designing novel in-fiber devices. For example, the polarization properties can be thermally tuned through the filled LC, resulting in high polarization dependent loss . The LPG in a fluid-filled PCF has a high thermal tuning coefficient of up to –1.58 nm/℃, which is due to the large thermo-optic coefficients of fluid . "
[Show abstract][Hide abstract]ABSTRACT: The authors review the recent advances in fabricating long-period gratings (LPGs) in photonic crystal fibers (PCFs). The novel
light-guiding properties of the PCFs allow the demonstration of novel sensors and devices based on such LPGs. The sensitivity
of these PCF LPGs to temperature, strain and refractive index is discussed and compared with LPGs made on conventional single-mode
fibers. In-fiber devices such as tunable band rejection filters, Mach-Zehnder interferometers are discussed.
KeywordsPhotonic crystal fiber–long-period grating–optical fiber sensor