The optical impulse distributed compensator, and the optical pulse compression vessel, the semiconductor short pulse laser component and the optical communication system null which use

摘要

PROBLEM TO BE SOLVED: To obtain a continuous fine adjusting function for group speed variance by providing a large group speed variance compensating function by inter-mode coupling between optical waveguides. ;SOLUTION: The large group speed variance compensating function is obtained by the inter-mode coupling between the optical waveguides which are formed of a semiconductor material and have different sectional shapes. The optical waveguides are so designed that light of a TE₀ mode is propagated only by the optical waveguide 5 in a mode conversion area 7 and light of a coupling mode of TE₂ of the optical waveguide 4 and TE₀ mode of the optical waveguide 5 is propagated in a mode coupling area (group speed variance compensation area) 8. When the optical waveguides 4 and 5 in the mode conversion area are present, the propagation constants of the modes are denoted as β₁ and β₂ and the coupling constant when the modes are coupled together is denoted as κ. When positive group speed variance is obtained by coupling TE₀ and TE₂ in phase in the mode coupling area, the thickness of a buffer layer 3 of the mode conversion area 7 is so determined that κ=-δ. Here, δ=(β₁-β₂)/2. For opposite-phase coupling, κ=δ.;COPYRIGHT: (C)1998,JPO