Title :
Laser-trimmed four-port bandpass filter fabricated in single-mode photosensitive Ge-doped planar waveguide
Author :
Kashyap, R. ; Maxwell, G.D. ; Ainslie, B.J.
Author_Institution :
Britsh Telecom Lab., Ipswich, UK
Abstract :
A single-mode photosensitive waveguide Mach-Zehnder interferometer fabricated in Ge-doped planar silica is reported. Two-millimeter-long identical-wavelength reflection gratings using external UV beams have been written into each arm to demonstrate a four-port bandpass device for the first time using this technology. The imbalance in the arms after writing of the gratings is compensated by laser trimming of one photosensitive arm of the interferometer. A 96.8% reflection of the output port is measured, and 58.8% of the total power available at the input at 1.5558 mu m in the bandpass of 1 nm is transmitted at the second input port after laser trimming. The total fiber-to-fiber insertion loss of the device is measured to be 1.35 dB.<>
Keywords :
diffraction gratings; germanium compounds; integrated optics; light interferometers; optical communication equipment; optical filters; optical losses; optical waveguides; silicon compounds; 1.35 dB; 1.5558 micron; 58.8 percent; Ge-doped planar waveguide; GeO/sub 2/-SiO/sub 2/; IR; bandpass filters; external UV beams; fiber-to-fiber insertion loss; four-port bandpass filter; grating writing; identical-wavelength reflection gratings; interferometer arms imbalance; laser trimmed integrated optics; laser trimming; semiconductors; single-mode photosensitive waveguide Mach-Zehnder interferometer; total power; Arm; Band pass filters; Fiber lasers; Gratings; Laser beams; Optical reflection; Planar waveguides; Silicon compounds; Waveguide lasers; Writing;
Journal_Title :
Photonics Technology Letters, IEEE
