Optical waveguides – Planar optical waveguide
Patent
1996-12-26
1998-11-24
Ngo, Hung N.
Optical waveguides
Planar optical waveguide
385 32, 385 45, 385 14, 385132, 385147, G02B 626
Patent
active
058419292
ABSTRACT:
A light wavelength filtering circuit in a wavelength-division multiplexing light communication system minimizes transmission loss in the waveguide after wavelength discrimination by having a linear output waveguide added to an output end of a light wavelength discriminating element, at which a signal having a long wavelength is outputted. A curved output waveguide is added to the rear stage of the output end at which a signal having a relatively short wavelength is outputted. Hence, a radiation loss at the output waveguide at the output end is minimized, while a space between the output light waveguides is being widened. Additionally, a core layer bandgap wavelength at the output waveguide of the long wavelength signal is set to be longer than a core layer band gap wavelength in another region. Hence, a substantial light confinement is formed in a horizontal direction even in the output waveguide at the long wavelength signal side and even if the output waveguide at the long wavelength signal side is curved, and the radiation loss can be reduced.
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Hamamoto Kiichi
Hayashi Masako
Komatsu Keiro
Sasaki Tatsuya
Takeuchi Takeshi
NEC Corporation
Ngo Hung N.
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