Efficient pulse compression using tapered photonic crystal fiber at 850 nm

Abstract

By using appropriate self-similar scaling analysis, we delineate the generation of linearly chirped solitary pulses in photonic crystal fiber (PCF) at 850 nm to obtain the short pulses with large compression factor and minimal pedestal energy when compared to adiabatic compression scheme. The dispersion and nonlinearity varying nonlinear Schrödinger equation aptly models the pulse propagation in such a PCF. The analytical results demand that the effective dispersion must decrease exponentially while the nonlinearity must increase exponentially in the PCF. Thus, based on the analytical results, we propose the new design of tapered PCF by varying the pitch and diameter of the air hole. We adopt the projection operator method to derive the pulse parameter equations which indeed very clearly describe the self-similar pulse compression process at different parts of the PCF structures. As we are interested in constructing compact compressor, we also introduce another designing of PCF by filling chloroform in the core region. The chloroform filled tapered PCF exhibits low dispersion length for efficient pulse compression with low input pulse energy over small propagation distances.