New design of 1x3 wavelength demultiplexer based on tilted grating in glass waveguide for first window operating wavelength

Abs tract: In this paper, an overview of modeling work emp loyed tilted Bragg grating filter in glass waveguide for a novel demultiplexer desi gn is presented. The desi gn is focused to operate in the firs t window wavelength band but extensi on to other windows is possi ble by modifying the grating period. Investigations are carried out to show the dependences of power reflection on the Bragg structural parameter (tilt a n g le ). By utilizing IFO_Grating s oftware applying coupled-mode theory, the res ults indicated that th e p ro p a g ating power is reflected significantly if the tilt angle is less than 10 and o shows no reflectance above this angle. Further numerical simulation with BPM tech n iq u e u s in g BPM_CAD, demonstrated that a substantial am ount of power can be deflected from the main waveguide by blazed Bragg grating structure. More than six wavelengths using channel spacing above 100 nm can be s eparated w h e n u t ilizing the model with over 88% of reflected output power. W ith th e limitatio n o f the BPM method, the tilt angle of more than 45 is considered. From this study, an o intuitive understandi ng of the spectral behaviors of the tilted fiber grating and an aid to desi gning and optimizing the devices for demultiplexer application is obtained.