Distributed Raman amplifiers (DRAs) are an enabling technology for long- haul and metropolitan- area broadband optical networks. These devices utilize the stimulated Raman scattering process in order to achieve gain over the bandwidth of ~ 40 THz from the transmission fiber itself. While DRAs’ offer various advantages by their ubiquitous presence in the transmission path, they also pose challenges such as gain flattening in the broadband spectral regime. Evidently, one cannot use fiber Bragg gratings (FBGs) and other filtering devices such as thin-films filters. However, gain flattening over wideband can be achieved using multi–wavelength (multi-λ) pumping , that is accomplished with spectral slicing based on Raman fiber lasers (RFLs). Novel test amplifiers have been designed and simulated with various pump parameters such as the number of RFLs pumps, their wavelengths, and relative powers. The results obtained using a 6-λ pump module in the range 1460-1510 nm, showed a better gain-flattened amplification . We have designed various network test topologies, which are simulated using commercially available software packages. A 6- λ pump module using 2 to 5 pairs of fiber Bragg gratings  seems optimal. The output FBGs are tunable in order to provide reconfigurable pump module. Details of the results and design optimization will be presented.
 Y. Cao, M. Y. A. Raja, “Gain-Flattened Ultra Wide Band Fiber Amplifiers,” J. Opt. Eng., Vol. 42,
No. 12, 3347-3451 (2003).
 Y. Cao, J. G. Naeini, K. Ahmad, and M. Y. A. Raja, “Gain-flattened Distributed Raman
Amplification using Multi-l Raman Fiber Laser Pumping”, presented in OISE’03, Orlando, FL.
The operating characteristics of a simple self-starting mode-locked erbium fiber ring laser based on a commercial optical fiber gain module are described. The laser produces pulses of the order of 50 mW. In contrast to earlier lasers of the same type, no polarizing element was needed in the ring to initiate mode locking. the implications of this fact relative to possible mechanisms for mode locking are discussed.
We report the development of a simple self starting passively mode locked diode pumped laser oscillator utilizing erbium doped fiber and a minimum number of readily available components. With pump powers as low as 8.0 mw, the oscillator generates stable pulses of 1.2 ns width and rates of 5.0 MHz at wavelengths around 1.55 micrometers . Evidence exists for substructure as short as 35 ps within the 1.2 ns pulses. A mechanism for the observed characteristics of the oscillator based on the all optical Kerr effect is proposed.
A tunable erbium doped fiber ring laser, pumped with a 980 nm InGaAs diode laser was constructed. Output power as a function of pump power and output wavelength for a given fiber length was measured. Spectral and temporal analysis of the signal showed mode-locked pulses of short duration and broad frequency content, as well as a CW component confined to a relatively narrow optical frequency range. The mechanisms for this type of mode-locking are discussed as well as the limitations placed on the lasing line width and spectral tunability.
In response to widespread applications of photonics and increasing needs of industry for qualified personnel, a B.S. program in Photonics was implemented in the fall of 1989 at the State University of New York (SUNY) Institute of Technology,
Utica, New York. The curriculum was developed recognizing the strong interdependence of photonics and electronics. It was also made flexible so that the students could move to other areas of science and engineering. This article describes the program and reviews the current applications of photonics which affect the program curriculum. It is expected that the graduates from this program will be better equipped to find suitable jobs and function more effectively in industry.