Osamu Aso

A 104 GHz 328 fs soliton pulse train generation through a comb-like dispersion profiled fiber using short high nonlinearity dispersion fibers

We have constructed a 693.6 m long comb-like dispersion profiled fiber using a newly developed high-nonlinearity DSF, through which a dual frequency beat signal was compressed by 14.7 times to generate a 104 GHz train of 328 fs pulses.

Effect of modulational instability on broadband wavelength conversion using four-wave mixing in optical fiber

We show that, in fiber-optic four-wave mixing based wavelength conversion, modulational instability compensates for the flatness degradation of the conversion efficiency due to birefringence. A 76 nm ultra-broadband 1 dB highly-flattened wavelength conversion with conversion efficiency up to /spl sim/4 dB is demonstrated.

Efficiency of highly nonlinear fiber in soliton converter for 40 Gbit/s 10,000 km fiber transmission

We show that highly nonlinear fiber is essential to reduce the input power, length, loss, and noise of a soliton converter, and that it actually halves the input power and length compared with a conventional DSF in 40 Gbit/s 10,000 km transmission.

Application of Nonlinear Fitting for Etalon-Type Gain-Flattening Filter Design

We describe a method of designing an etalon-type gain-flattening filter. The method is based on nonlinear fitting of transmission spectra of combined etalons, and it enables us to design gain-flattening filters that exhibit better compensation of any spectra than conventional methods. By manufacturing a typical filter module, we demonstrate excellent gain-flattening behavior applicable to the C-band optical amplifier for metro transmission systems.

Unitarity-conserving construction of the Jones matrix and its application to polarization-mode dispersion analysis

We propose a method to measure the Jones matrix of the transmission medium without violating the unitarity of the matrix. Our method consists of defining the normalized Jones matrix each time the unitarity is lost by experimental error. Numerical simulation is performed to show the feasibility of the proposed method. The method is applied to polarization-mode dispersion analysis. We derive an explicit expression that allows us to evaluate the polarization-mode dispersion vector directly from the elements of the Jones matrix. We also introduce a parameter ∑ to determine a suitable wavelength step size for the measurement of the differential group delay of the principal states of polarization.