Generation of femtosecond pulses by passive mode-locking of broad-band lasers using bacteriorhodopsin films

摘要

Closed-form analysis of passive mode-locking of homogeneously broadened broad-band laser systems using bacteriorhodopsin films as slow saturable absorber is presented. The analysis consists of the self-consistent approach to obtain the closed-form solutions to the mode-locked pulse energy and pulse width. The dependence of mode-locked pulse energy and pulse width on the system parameters such as the thickness of the film, the total number density of active molecules, the initial number density of molecules in B-state and the gain of the laser medium are presented in the graphical form. The analysis shows that passive mode-locking of a typical broad-band laser system like Ti: sapphire using bacteriorhodopsin film of thickness 50 #mu#m can generate pulses of approx=58 fs duration with approx=90 nJ energy.