An electro-optically tunable interleaver filter based on an analogue birefringent structure is optimally designed. It is feasible to achieve small channel spacing (≤ 50 GHz), a wide pass-band and stop-band (>1/5 period), high isolation (−30 dB) and electro-optical tunability simultaneously without using large birefringent crystals. A simple experiment verifies the feasibility of achieving electro-optic tunability in principle. A highly efficient electro-optic configuration, which needs the lowest operating voltage and shows no walk-off effect when an extraordinary ray propagates through the electro-optic crystal plates in the analogue birefringent structures, is proposed and analysed.

Optimum design of a novel electro-optically tunable birefringent interleaver filter

A listing of articles, books and conference proceedings dealing with ferroelectric and related materials published throughout the world and covering mainly the period January to March 1970

Bibliography of ferroelectrics

Tunable interleaver filters are very important in DWDM applications. To be effective, it is required that the filters must possess wide passband (or stopband) width, high isolation, small channel spacing, high tuning speed an so on simultaneously. Whereas, for the small birefringence of all the natural crystals and synthesized crystals, it is quite difficult for the available birefringent interleavers to have the channel spacing smaller than 50GHz and other properties mentioned above simultaneously. This paper proposes a novel electro-optically tunable birefringent interleaver filter, which solves the problem successfully. It is based on cascaded analog birefringent structures. The filter of this configuration can achieve small channel spacing (≤50GHz), wide passband and stopband width (>1/5 period) and high isolation (<-30dB). When voltage is applied on electro-optical crystal plates in analog birefringent structures, the filter also possesses the function of high-speed (submicrosecond) center-frequency tunability simultaneously. A most efficient electro-optic configuration, which needs the lowest operating voltage and has not walk-off effect of extraordinary ray in the crystals, is proposed and analyzed. A prototypical experiment verifies the electro-optic tunability of this filter as well.

High performance electro-optically tunable birefringent interleaver filters

Chapter ii – nonlinear dielectric effects

The most general expression for the half-wave voltage of a LiNbO 3 transverse light modulator has been studied. As a result, a novel cut with a minimum half-wave voltage of 1440 V for amplitude modulation is proposed. A preliminary experimental verification confirms the promising theoretical results.

F. Librecht

Papers

Optimum cut for a LiNbO 3 transverse light modulator