Transmission characteristics of optical asymmetric Y junction with a gap region

A novel type of asymmetric Y junction structure is proposed. This Y junction has a gap region so that the required power splitting ratio can be obtained simply even when the branching angle is kept fixed. The transmission characteristics of the proposed Y junction are simulated by means of a beam propagation method (BPM). It is shown that this Y junction has a marked advantage of flexibility in practical use over the conventional asymmetric Y junction. It is estimated that, when the configuration is applied to the 3-dB power divider, a drastic reduction in radiation losses compared with usual symmetric Y junction results.<
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