Title :
Low-loss spot-size transformer by dual tapered waveguides (DTW-SST)
Author :
Yamaguchi, Naoaki ; Kokubun, Yasuo ; Sato, K.
Author_Institution :
Toshiba Corp., Tokyo, Japan
fDate :
4/1/1990 12:00:00 AM
Abstract :
The reduction of the insertion loss of a spot-size transformer based on dual tapered waveguides (DTW-SST) by controlling the shape of the tapered portion is discussed. The transformer is easily fabricated using a shadow mask sputtering method. A method is described for controlling independently the parameters of the tapered portion, such as the maximum taper angle, and length, and the position of tapered portion with respect to the edge of the shadow mask. A large transformation ratio (5 and 1/5) and a low insertion loss (0.7 dB) have been obtained
Keywords :
optical couplers; optical losses; optical waveguides; 0.7 dB; dual tapered waveguides; insertion loss; low insertion loss; mask edge; maximum taper angle; optical couplers; shadow mask; shadow mask sputtering method; spot-size transformer; tapered portion length; tapered portion position; tapered portion shape control; transformation ratio; waveguide tapered portion; Insertion loss; Optical refraction; Optical variables control; Optical waveguides; Refractive index; Semiconductor waveguides; Shape control; Sputtering; Transformer cores; Waveguide transitions;
Journal_Title :
Lightwave Technology, Journal of
