PQE 2005 1

1
Two-photon absorption standards in the 550-1600
nm excitation range establishing a correction
curve for accurate cross section calibration
Nikolay S. Makarov, Mikhail Drobizhev, Aleksander
Rebane Department of Physics, Montana State
University, Bozeman, MT
2
Outline

• Motivation
• Experimental setup
• Pulse duration
• Beam profile
• Correction curve
• 2PA standards, example
• Conclusions

3
Motivation
If the 2PA reference standards were available
Absolute 2PA cross section
Relative 2PA spectrum
If there are no standards (establishing
standards)
Absolute 2PA cross section
Relative 2PA spectrum
Correction curve
4
Experimental setup
laser system
Coherent VERDI CW 532nm
Coherent MIRA 900
OPA wavelength control
PC LabView
color filters
pol.
serial control
Coherent LEGEND-HE regen. amplifier, 1kHz
TOPAS-C
filter wheel control
USB control
SHG crystal
pulse characterization
GPIB
spectrometer CCD control
FW
digital oscilloscope
FROG
autocorrelator
ref. detector
l/2
PH1
LN CCD
L1
600 l mm-1
sample
M1
PH2
spectrometer
5
Pulse duration
SH signal
SH idler
Signal
Measured with SHG autocorrelator Clark MXR
AC-150 70 140 fs pulse duration range 5
fixed wavelength measurement error 3
step-to-step relative measurement error
6
Beam profile
SH signal
Signal
SH idler
Measured with CCD camera Xillix MicroImager
PMI1400 0.03 0.10 cm diameter range 4
fixed wavelength measurement error
7
Correction curve
8 fixed wavelength measurement error 3
step-to-step relative measurement error
8
2PA standard Rhodamine 6G
9
2PA standard Rhodamine B
10
2PA standards Full set
11
Conclusions

• 2PA of 15 commercially available dyes in
  5501600 nm
• ? 10 estimated accuracy of 2PA cross sections
• Values are in good agreement with literature
  data (fluorescence technique)
• Data can be used as reference for determining
  absolute 2PA cross sections and spectra

Acknowledgement
This work is supported by AFOSR Grant No.
FA9550-05-1-0357