Fiber Delivery of Sub-10-fs Pulses for Nonlinear Optical Microscopy

摘要

Broadband, sub-10-fs pulses, can be propagated through polarization maintaining silica core single mode fibers for use in NLOM. In a manner similar to all fiber chirped pulse amplifiers, we stretch the pulse sufficiently, ?-4000 fs~2 post fiber residual chirp, such that nonlinearity is minimized owing to the significant impact of dispersion on pulse width. The optics of the imaging system provide the remaining positive dispersion delivering a near transform limited, 12.7 fs pulse, to the specimen plane. We are able to achieve average powers up to 75 mW from the fiber with minimal changes in spectra at a fiber length of 400 mm. Image intensity analysis of identical images taken with and without the fiber indicates that the fiber based system is capable of generating signals that are within a factor of two of our traditional NLOM. Autocorrelations and pulse spectra are also presented following propagation through the fiber and imaging system.