Showing papers by "Koji Igarashi published in 2001"
TL;DR: In this article, a single-stage step-like dispersion profiled fiber (SDPF) was used to compress 5 ps optical pulses down to 20 fs by a 15.1m-long single-stage steplike SDPF through a series of higher-order soliton compression processes.
Abstract: It has been successfully demonstrated to compress 5 ps optical pulses down to 20 fs by a 15.1-m-long single-stage step-like dispersion profiled fiber (SDPF) through a series of the higher-order soliton compression processes in conjunction with a single and ordinary erbium-doped fiber preamplifier. The SDPF compressor contains two kinds of dispersion-flattened fibers (DFFs) at its end and was composed by fiber-splicing with an aid of an extremely careful cutback method. In addition, we have compared the measured compression profiles in the 20–100 fs range with simulation results calculated on the bases of a few elementary soliton models and some experimentally extracted parameters, which is aimed to investigate and clarify its compression mechanism. It was found out that the standard nonlinear Schroedinger equation works appropriately to some extent even in the 30–100 fs range for the DFF used here, although some difficulty exists in modeling the pulse width evolution in the sub-30 fs range as far as the parameters that we used are concerned.
14 citations
TL;DR: In this article, a fiber-optic soliton compressor for the generation of sub-100 femtosecond (fs) optical pulses out of diode laser pulses is presented.
Abstract: We report our studies on a fiber-optic soliton compressor for generation of sub-100 femtosecond (fs) optical pulses out of picosecond (ps) diode laser pulses. The soliton compressor is rather simple and composed of a 15 ∼ 20 m-long step-like dispersion profiled fiber (SDPF) in conjunction with a single Er-doped fiber amplifier (EDFA). Careful design of such a SDPF compressor was performed, leading to demonstration of 20-fs class compression performance, and experimental investigation was carried out in detail on the optical pulse propagation in the compression processes. In addition, nonlinear fiber loops were applied to suppression of pulse pedestals, resulting successfully in high quality optical pulses of the 100-fs range.
7 citations
11 May 2001
TL;DR: In this article, a new scheme of detecting PPM coded optical data was proposed based on the trial fabrication of an all-optical gating module composed of quantum well saturable absorber switches and a diffractive optic platform.
Abstract: Summary form only given. Based on the trial fabrication of an all-optical gating module composed of quantum well saturable absorber switches and a diffractive optic platform, a new scheme of detecting PPM coded picosecond optical data was proposed. The time-windowing gates efficiently suppress ASE noise of preamplifier, and increase reliability. With this mass-producible module the picosecond optics is open for the massive application areas such as local area networks.
15 Nov 2001
TL;DR: In this paper, a single-stage step-like dispersion profiled fiber (SDPF) was used to compress 5 ps optical pulses down to 20 fs by a 15.1m-long single-stage steplike SDPF through a series of higher-order soliton compression processes.
Abstract: It has been successfully demonstrated to compress 5 ps optical pulses down to 20 fs by a 15.1-m-long single-stage step-like dispersion profiled fiber (SDPF) through a series of the higher-order soliton compression processes in conjunction with a single and ordinary erbium-doped fiber preamplifier. The SDPF compressor contains two kinds of dispersion-flattened fibers (DFFs) at its end and was composed by fiber-splicing with an aid of an extremely careful cutback method. In addition, we have compared the measured compression profiles in the 20–100 fs range with simulation results calculated on the bases of a few elementary soliton models and some experimentally extracted parameters, which is aimed to investigate and clarify its compression mechanism. It was found out that the standard nonlinear Schroedinger equation works appropriately to some extent even in the 30–100 fs range for the DFF used here, although some difficulty exists in modeling the pulse width evolution in the sub-30 fs range as far as the parameters that we used are concerned.