Highly birefringent hollow-core photonic bandgap fiber

Abstract

A hollow-core photonic band-gap fiber with very high group birefringence is fabricated and characterized. Two independent methods, wavelength scanning and direct measurement of differential group delay (DGD), are used to obtain the group beatlength and group birefringence. The fiber illustrates a very high group birefringence of 0.025 at 1550 nm. The wavelength dependence of the group beatlength and group birefringence are also analyzed.

Light propagation in highly birefringent photonic liquid crystal fibers

“…Due to the fact that PM−1550−01 fiber is highly birefringent, the output state of polarization is wavelength dependent and as a result a modulation in the transmission spectrum can be observed. Wavelength spacing between neighbouring peaks (maxima) Dl depends on the group birefringence and the fiber length L. Hence, the value of the group birefringence G can by cal− culated by using the following formula [8,9] …”

“…Birefringence in PCFs usually results from accidental asymmetries in the cladding−hole lattice or from intentional manipulation of the core and/or cladding structure [6][7][8]. In characterization of PCFs, one practical issue is the birefrin− gence measurement.…”

“…In general, the phase and group birefringences can have different values and therefore it is important to be able to measure them both [7][8][9].…”

Demodulation of DPSK signals up to 40 gb/s using a highly birefringent photonic bandgap fiber

“…Temperature-insensitive Sagnac interferometers have been demonstrated using solid core photonic crystal fibers [14], [15] and the low-temperature dependence of the birefringence of PBG fibers has also been confirmed experimentally [7]. Finally, the fiber design can be optimized further in order to achieve even larger values of form birefringence [16], [17].…”

Ultrahigh birefringence index-guiding photonic crystal fiber

“…The highest birefringence reported for fabricated index-guiding PCFs was in the order of 10 -3 [2,3]. It should be noted that the highest group birefringence reported were found in a photonic bandgap fiber (0.025 at the wavelength of 1550nm), achieved via elliptical air-core [4]. However, such fiber does not allow the inscription of fiber gratings in its core.…”