A femtosecond-pulsed tunable optical parametric generator at 1530-1790 nm for label-free third harmonic generation imaging

Johanna Tragardh, Gillian Robb, Kamal Gadalla, Stuart Cobb, Christopher Travis, Gian-Luca Oppo, Gail McConnell

Research output: Contribution to conferenceAbstract

Abstract

We have developed a simple tunable optical parametric generator (OPG), emitting broad band ultrashort pulses at around 1550 nm, that is suitable for nonlinear microscopy. The OPG consists of a periodically poled lithium niobate (PPLN) crystal, pumped at 1064 nm by a high pulse energy ultrafast fiber laser (Fianium HE1060-1uJ-fs). Because of the high pulse energy of the pump laser (1 J), it is not necessary to build a cavity around the PPLN crystal, and the long wavelength output is generated simply by focusing the pump light into the crystal. The output pulses have a band-width of about 130 nm and a pulse width of 300 fs. The OPG is tunable from 1530 nm to 1790 nm by using the multiple regions with different poling periodicity in the PPLN crystal, and can be fine-tuned by changing the temperature of the crystal. The output power at 1550 nm is 100 mW, which is sufficient for non-linear microscopy, even when taking into account the reduced transmission of the microscope optics at these long wavelengths. In addition, light throughout the visible spectrum and into the NIR is also generated in the PPLN crystal and could potentially be used for (simultaneous) single and two-photon imaging.We demonstrate the use of this OPG for label-free THG imaging of a 200 m thick fixed section of mouse brain. The output pulses from the OPG have high enough peak power that we can generate THG using moderate excitation powers at the specimen plane (< 15 mW), due to the low repetition rate of the laser (1 MHz). A higher 80 MHz repetition rate laser, such as commercially available OPOs, would, because of their lower peak power, require a much higher average power to generate the signal, likely causing sample damage. We observe very little change in sample morphology over 30 minutes of continuous imaging, which suggests that this approach does not cause significant photo-damage.
LanguageEnglish
Publication statusPublished - 25 Jun 2015
EventCLEO Europe - EQEC 2015 - Munich, Germany
Duration: 21 Jun 201525 Jun 2015

Conference

ConferenceCLEO Europe - EQEC 2015
CountryGermany
CityMunich
Period21/06/1525/06/15

Fingerprint

harmonic generations
generators
lithium niobates
crystals
pulses
output
repetition
pumps
damage
microscopy
lasers
visible spectrum
wavelengths
brain
fiber lasers
mice
periodic variations
pulse duration
microscopes
optics

Keywords

  • optical parametric generator
  • harmonic generation imaging
  • imaging

Cite this

@conference{16e906ef60ef4dd2a240752505b21c91,
title = "A femtosecond-pulsed tunable optical parametric generator at 1530-1790 nm for label-free third harmonic generation imaging",
abstract = "We have developed a simple tunable optical parametric generator (OPG), emitting broad band ultrashort pulses at around 1550 nm, that is suitable for nonlinear microscopy. The OPG consists of a periodically poled lithium niobate (PPLN) crystal, pumped at 1064 nm by a high pulse energy ultrafast fiber laser (Fianium HE1060-1uJ-fs). Because of the high pulse energy of the pump laser (1 J), it is not necessary to build a cavity around the PPLN crystal, and the long wavelength output is generated simply by focusing the pump light into the crystal. The output pulses have a band-width of about 130 nm and a pulse width of 300 fs. The OPG is tunable from 1530 nm to 1790 nm by using the multiple regions with different poling periodicity in the PPLN crystal, and can be fine-tuned by changing the temperature of the crystal. The output power at 1550 nm is 100 mW, which is sufficient for non-linear microscopy, even when taking into account the reduced transmission of the microscope optics at these long wavelengths. In addition, light throughout the visible spectrum and into the NIR is also generated in the PPLN crystal and could potentially be used for (simultaneous) single and two-photon imaging.We demonstrate the use of this OPG for label-free THG imaging of a 200 m thick fixed section of mouse brain. The output pulses from the OPG have high enough peak power that we can generate THG using moderate excitation powers at the specimen plane (< 15 mW), due to the low repetition rate of the laser (1 MHz). A higher 80 MHz repetition rate laser, such as commercially available OPOs, would, because of their lower peak power, require a much higher average power to generate the signal, likely causing sample damage. We observe very little change in sample morphology over 30 minutes of continuous imaging, which suggests that this approach does not cause significant photo-damage.",
keywords = "optical parametric generator, harmonic generation imaging, imaging",
author = "Johanna Tragardh and Gillian Robb and Kamal Gadalla and Stuart Cobb and Christopher Travis and Gian-Luca Oppo and Gail McConnell",
year = "2015",
month = "6",
day = "25",
language = "English",
note = "CLEO Europe - EQEC 2015 ; Conference date: 21-06-2015 Through 25-06-2015",

}

A femtosecond-pulsed tunable optical parametric generator at 1530-1790 nm for label-free third harmonic generation imaging. / Tragardh, Johanna; Robb, Gillian; Gadalla, Kamal; Cobb, Stuart; Travis, Christopher; Oppo, Gian-Luca; McConnell, Gail.

2015. Abstract from CLEO Europe - EQEC 2015, Munich, Germany.

Research output: Contribution to conferenceAbstract

TY - CONF

T1 - A femtosecond-pulsed tunable optical parametric generator at 1530-1790 nm for label-free third harmonic generation imaging

AU - Tragardh, Johanna

AU - Robb, Gillian

AU - Gadalla, Kamal

AU - Cobb, Stuart

AU - Travis, Christopher

AU - Oppo, Gian-Luca

AU - McConnell, Gail

PY - 2015/6/25

Y1 - 2015/6/25

N2 - We have developed a simple tunable optical parametric generator (OPG), emitting broad band ultrashort pulses at around 1550 nm, that is suitable for nonlinear microscopy. The OPG consists of a periodically poled lithium niobate (PPLN) crystal, pumped at 1064 nm by a high pulse energy ultrafast fiber laser (Fianium HE1060-1uJ-fs). Because of the high pulse energy of the pump laser (1 J), it is not necessary to build a cavity around the PPLN crystal, and the long wavelength output is generated simply by focusing the pump light into the crystal. The output pulses have a band-width of about 130 nm and a pulse width of 300 fs. The OPG is tunable from 1530 nm to 1790 nm by using the multiple regions with different poling periodicity in the PPLN crystal, and can be fine-tuned by changing the temperature of the crystal. The output power at 1550 nm is 100 mW, which is sufficient for non-linear microscopy, even when taking into account the reduced transmission of the microscope optics at these long wavelengths. In addition, light throughout the visible spectrum and into the NIR is also generated in the PPLN crystal and could potentially be used for (simultaneous) single and two-photon imaging.We demonstrate the use of this OPG for label-free THG imaging of a 200 m thick fixed section of mouse brain. The output pulses from the OPG have high enough peak power that we can generate THG using moderate excitation powers at the specimen plane (< 15 mW), due to the low repetition rate of the laser (1 MHz). A higher 80 MHz repetition rate laser, such as commercially available OPOs, would, because of their lower peak power, require a much higher average power to generate the signal, likely causing sample damage. We observe very little change in sample morphology over 30 minutes of continuous imaging, which suggests that this approach does not cause significant photo-damage.

AB - We have developed a simple tunable optical parametric generator (OPG), emitting broad band ultrashort pulses at around 1550 nm, that is suitable for nonlinear microscopy. The OPG consists of a periodically poled lithium niobate (PPLN) crystal, pumped at 1064 nm by a high pulse energy ultrafast fiber laser (Fianium HE1060-1uJ-fs). Because of the high pulse energy of the pump laser (1 J), it is not necessary to build a cavity around the PPLN crystal, and the long wavelength output is generated simply by focusing the pump light into the crystal. The output pulses have a band-width of about 130 nm and a pulse width of 300 fs. The OPG is tunable from 1530 nm to 1790 nm by using the multiple regions with different poling periodicity in the PPLN crystal, and can be fine-tuned by changing the temperature of the crystal. The output power at 1550 nm is 100 mW, which is sufficient for non-linear microscopy, even when taking into account the reduced transmission of the microscope optics at these long wavelengths. In addition, light throughout the visible spectrum and into the NIR is also generated in the PPLN crystal and could potentially be used for (simultaneous) single and two-photon imaging.We demonstrate the use of this OPG for label-free THG imaging of a 200 m thick fixed section of mouse brain. The output pulses from the OPG have high enough peak power that we can generate THG using moderate excitation powers at the specimen plane (< 15 mW), due to the low repetition rate of the laser (1 MHz). A higher 80 MHz repetition rate laser, such as commercially available OPOs, would, because of their lower peak power, require a much higher average power to generate the signal, likely causing sample damage. We observe very little change in sample morphology over 30 minutes of continuous imaging, which suggests that this approach does not cause significant photo-damage.

KW - optical parametric generator

KW - harmonic generation imaging

KW - imaging

UR - http://2015.cleoeurope.org/

M3 - Abstract

ER -

Tragardh J, Robb G, Gadalla K, Cobb S, Travis C, Oppo G-L et al. A femtosecond-pulsed tunable optical parametric generator at 1530-1790 nm for label-free third harmonic generation imaging. 2015. Abstract from CLEO Europe - EQEC 2015, Munich, Germany.