Continuously tunable multi-wavelength transmission filter based on a stabilised fibre-optic interferometer

A simple technique for implementing all-fiber interleaver for DWDM systems

“…Such a configuration could separate/interleave the wavelength channels with a sinusoidalresponse function [3,4,7]. An important requirement in realizing DWDM-specific interleavers based on MZIs is to set the differential phase delay ⌬ precisely between the arms of the interferometer [3,5,6]. This can be achieved either by introducing a differential path length ⌬L [3,5] or by inducing a specific change in n eff of the guided mode in one of the arms of the MZI [6].…”

“…An important requirement in realizing DWDM-specific interleavers based on MZIs is to set the differential phase delay ⌬ precisely between the arms of the interferometer [3,5,6]. This can be achieved either by introducing a differential path length ⌬L [3,5] or by inducing a specific change in n eff of the guided mode in one of the arms of the MZI [6]. Inducing a change in refractive index by ion bombardment [6] involves a complex procedure, and there is a possibility of drift in the channel wavelength due to slow changes in refractive index with time.…”

“…Other reported methods [3,5] to tune the interleaver response through ⌬L involve real-time mechanical stretching of the fiber, and are at best suited to coarse-WDM systems. To the best of our knowledge, tuning of the FSR of all-fiber wavelength interleavers suitable for DWDM transmission, with channel spacing of 50 GHz or less, has not been reported previously.…”

“…Of the few alternative routes followed to realize a wavelength interleaver, the one based on unbalanced MZI is perhaps the most popular [1][2][3][4], and it can be realized either in an integrated optic form [4] or in an all-fiber form [2]. To realize an all-fiber interleaver and tune its spectral response to match the ITU grids, is the challenge faced by telecommunication engineers [3,5,6]. In this paper, we report a simple all-fiber approach to tune the differential phase delay ⌬ between the two arms of an MZI-based wavelength interleaver, and hence its spectral response.…”

“…The bandwidth of conventional printed wide slot antenna is only around 10% to 20% [1,2]. Several techniques have been proposed to improve the operating bandwidth of this type of antenna [2][3][4][5]. However, in these studies, the bandwidth of the slot antenna still cannot cover the whole FCC-defined UWB frequency band (3.1-10.6 GHz).…”