Photonic-crystal fibers with a photonic band gap tunable within the range of 930-1030 nm

The physical principles of photonic-crystal fibers with a photonic band gap tunable in the visible and near-IR spectral ranges are demonstrated. Direc t numerical integration of the Maxwell equations with the use of the finite -difference time-domain technique reveals the possibility of creating holey fibers with a photonic-crystal cladding whose photonic band gap lies withi n the frequency range characteristic of widespread solid-state femtosecond lasers. The fabrication of holey fibers with a pitch of the two-dimensional periodic structure of the cladding less than 500 nm allowed us to experime ntally observe a photonic band gap in transmission spectra of holey fibers tunable within the range of 930-1030 nm. This photonic band gap is satisfac torily described within the framework of the proposed numerical approach ba sed on the finite-difference time-domain method. (C) 2000 MAIK "Nauka/Inter periodica".