A temperature insensitive InGaAsP-InP optical filter

A temperature insensitive optical filter (TIOF) with InGaAsP-InP material system is proposed. Less than 0.1 /spl Aring///spl deg/C temperature dependence is achieved for the first time even though we used the InGaAsP-InP material system. By changing the optimum structure of the TIOF, blue-shift temperature characteristics are also obtained. These two novel phenomena are in good agreement with the TIOF design principle.