Haruki Ogoshi

High-power erbium-doped fiber amplifier pumped by wavelength multiplexed semiconductor laser diode unit

High-power optical fiber amplifiers (OFAs) are needed in various optical transmission systems: wavelength-division multiplexing (WDM) systems, large passive splitting systems, long-haul repeaterless systems, analog distribution systems, etc. The use of high power pumping sources is one of the most important factors for high-power OFAs. High-power OFAs with various pumping sources are reported. We demonstrate a high-power Er-doped fiber amplifier (EDFA) pumped with wavelength multiplexed light from a MQW semiconductor laser diode unit.

Co-Propagating Dual-Order Distributed Raman Amplifier Utilizing Incoherent Pumping

We propose a distributed Raman amplifier available for dual-order co-propagating configuration with low-relative intensity noise (RIN) transfer. The first-order and second-order pumps are composed of incoherent and coherent light sources, respectively. By using the incoherent light source as a first-order pump, RIN transfer can be reduced. A semiconductor optical amplifier-based first-order incoherent light source for the configuration has been developed. The results of the RIN measurement and 22.5-Gbaud polarization-division multiplexing 16 quadrature amplitude modulation (PDM-16QAM) transmission experiment over 2720 km in a re-circulating loop show that the proposed configuration will be effective for a practical low-noise co-propagating Raman amplifier.

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.

Visible luminescence in 1480nm High Power Pumped Erbium-doped Fiber Amplifier

High power Erbium-doped fiber amplifier(EDFA) is required in various optical transmission systems such as Dense-WDM systems or free space transmission.

High-power polarization-maintaining dispersion-shifted EDFA

Summary form only given. We have developed fully engineered polarization-maintaining and dispersion-shifted Er-doped fiber amplifiers (EDFAs) using polarization-maintaining and absorption-reducing (PANDA) and dispersion shifted fiber structure erbium-doped fiber (PMDS-EDF).