Measuring the Raman time constant (TR) for soliton pulses in standard single-mode fiber

The Raman time constant (T-R) used in the generalized nonlinear Schrodinger equation is determined experimentally at 1550 mm based on the Raman self-frequency shift in a standard single-mode fiber. The effective value of the T-R as measured is found to be 3.0 fs. Detailed error analysis shows that the uncertainty in the measurement is less than +/-1.0 fs, The measured value of the T-R is approximately half of what is commonly used at present in theoretical simulations, Determined experimentally in this work the accurate value of T-R = 3.0 fs is essential in modeling pulse propagation in optical fibers.