Open AccessRapid, in-line, non-interferometric auto- and cross-correlator for microscopy
Author(s) -
Christopher N. LaFratta,
Pingqing Fu,
John T. Fourkas
Publication year - 2006
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.14.111215
Subject(s) - optics , laser , microscope , microscopy , ultrashort pulse , interferometry , materials science , numerical aperture , photodiode , interference microscopy , optoelectronics , physics , wavelength
We demonstrate a simple, in-line scheme for determining the duration of ultrafast pulses in the focal region of a high-numerical-aperture microscope objective. Photocurrent generated in a GaAsP photodiode by two-photon absorption of orthogonally-polarized laser beams that meet at a slight angle is used to autocorrelate lasers non-interferometrically. Cross-correlation between two lasers is also demonstrated. This setup, which can be built readily by a microscope user who is not an optics expert, allows for the rapid characterization of pulses that can be hundreds of fs long while making it possible for all of the laser intensity to be employed for nonlinear optical microscopy after the pulse duration has been measured.