Novel method to simultaneously compress pulses and suppress supermode noise in actively mode-locked fiber ring laser

A Novel OCDMA Thresholder Based on Nonlinear Polarization Rotation

“…The linear and nonlinear phase delay between the fast and slow axis components after the HNLF, which are induced by the linear and nonlinear birefringence respectively, can be expressed as follows [8]: and the output light power I out can be calculated using (2): where P is the input light power; is the attenuation rate of the VOA2; =2 / is the propagation constant; n x and n y are the linear birefringence coefficients; L=500m is the length of HNLF; =10W -1 km -1 is the nonlinear coefficient of the HNLF; 1 is the angle between the polarization direction of input signal and the polarization direction of the polarizer; 2 is the angle between the polarization direction of the polarizer and the fast axis of HNLF. The 1 and 2 can be adjusted by the polarization controllers PC1 and PC2.…”

Stabilization of mode-locked erbium-doped fiber laser

“…Onodera [51 designed a new composite cavity structure to reduce supermode noise. Li et al [6] used a novel method of nonlinear polarization rotation to suppress supermode noise. Yoshida et al [7] have showed that a phase-locked loop stabilized regenerative mode-locked fiber laser can produce stable and short optical pulses.…”

Multi wavelength rational harmonic mode locked source for polarization division multiplexing based on a reflective semiconductor optical amplifier and Bragg grating written in a high birefringent fiber

“…The instability of the optical pulse train from a fiber laser is generally originated from polarization fluctuations in the fiber cavity, length drift due to temperature fluctuations and independent supermodes [5]. In particular, the noise induced by the supermodes is one of the main noise sources in harmonic mode locked fiber lasers.…”