Flexible Polymeric Tunable Lasers for WDM Passive Optical Networks

Flexible polymer waveguide with a Bragg reflection grating is incorporated to form an external cavity laser with a wide tuning range, and it is evaluated as a tunable light source for wavelength division multiplexing optical communication systems. The highly elastic property of polymer materials makes them suitable for producing a tunable Bragg reflector controlled by an imposed strain. The flexible tunable Bragg reflector is installed on a compact moving stage 6 connected to a piezoelectric motor. By applying a total strain of 60680 με (6.07%), wavelength tuning of 82 nm is achieved with a side-mode suppression ratio of 43 dB and a linewidth less than 0.1 nm. The tunable laser controlled by a microactuator exhibits long-term stability with a wavelength fluctuation of less than 0.1 nm. In the optical transmission experiment, various wavelengths are used to transmit the 2.5 Gb/s signal over 50 km, excellent performance was observed with a power penalty of 1 dB compared to the DFB laser.