Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr 4+:Forsterite laser

D. A. Walsh, C. E. Crombie, W. Sibbett, C. T. A. Brown, V. G. Savitski, D. Burns, S. Calvez

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

1 Citation (Scopus)

Abstract

The ability to control the temporal output from a femtosecond laser can enable the same laser to be used for multiple functions, for example, the laser used in an optical tweezers system could be used as a constant-intensity source to trap a biological cell and then be temporarily switched to mode-locked operation to effect photoporation. Here, we report the rapid switching of a Cr 4+:forsterite laser between mode-locked and unmode-locked continuous wave (CW) regimes via the optical pumping of an intracavity SESAM element. Mode-locking of the laser was initiated by an intracavity quantum well (GaInAsN) SESAM having an anti-resonant design (ΔR∼0.3%, ?PL∼1310nm) that yielded transformlimited 89fs pulses centered around 1296nm with a repetition rate of 162MHz at an average power of 64mW. Upon excitation of the SESAM with 600mW of extra-cavity power from an 808nm semiconductor diode laser, switching could be induced between the unmode-locked and mode-locked regimes. Transitions free of Q-switching or relaxation oscillations were observed with <200μs switching times for both for the initiation and cessation of mode-locking. Periods of mode-locked operation of custom duration could be produced by appropriate control of the SESAM pump diode enabling the generation of bursts of pulses as short as 400μs. Switching was confirmed to originate from local pump-induced heating of the SESAM by observing the laser going through identical regime switching when the chip temperature of the 'unpumped' SESAM was raised by ∼20°C.

LanguageEnglish
Title of host publicationLaser Sources and Applications
Volume8433
DOIs
Publication statusPublished - 13 Jun 2012
EventLaser Sources and Applications - Brussels, Belgium
Duration: 16 Apr 201219 Apr 2012

Conference

ConferenceLaser Sources and Applications
CountryBelgium
CityBrussels
Period16/04/1219/04/12

Fingerprint

forsterite
Femtosecond
continuous radiation
Laser
Lasers
Mode-locking
Laser mode locking
lasers
Laser modes
Pump
Q-switching
Pumps
Q switching
Semiconductor diodes
Optical tweezers
Relaxation Oscillations
Optical pumping
locking
Optical Tweezers
Regime Switching

Keywords

  • femtosecond
  • forsterite
  • GaInAsN
  • laser
  • mode-locking
  • regime switching
  • SESAM
  • semiconductor lasers
  • quantum wells

Cite this

Walsh, D. A., Crombie, C. E., Sibbett, W., Brown, C. T. A., Savitski, V. G., Burns, D., & Calvez, S. (2012). Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr 4+:Forsterite laser. In Laser Sources and Applications (Vol. 8433). [84330G] https://doi.org/10.1117/12.922340
Walsh, D. A. ; Crombie, C. E. ; Sibbett, W. ; Brown, C. T. A. ; Savitski, V. G. ; Burns, D. ; Calvez, S. / Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr 4+:Forsterite laser. Laser Sources and Applications. Vol. 8433 2012.
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title = "Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr 4+:Forsterite laser",
abstract = "The ability to control the temporal output from a femtosecond laser can enable the same laser to be used for multiple functions, for example, the laser used in an optical tweezers system could be used as a constant-intensity source to trap a biological cell and then be temporarily switched to mode-locked operation to effect photoporation. Here, we report the rapid switching of a Cr 4+:forsterite laser between mode-locked and unmode-locked continuous wave (CW) regimes via the optical pumping of an intracavity SESAM element. Mode-locking of the laser was initiated by an intracavity quantum well (GaInAsN) SESAM having an anti-resonant design (ΔR∼0.3{\%}, ?PL∼1310nm) that yielded transformlimited 89fs pulses centered around 1296nm with a repetition rate of 162MHz at an average power of 64mW. Upon excitation of the SESAM with 600mW of extra-cavity power from an 808nm semiconductor diode laser, switching could be induced between the unmode-locked and mode-locked regimes. Transitions free of Q-switching or relaxation oscillations were observed with <200μs switching times for both for the initiation and cessation of mode-locking. Periods of mode-locked operation of custom duration could be produced by appropriate control of the SESAM pump diode enabling the generation of bursts of pulses as short as 400μs. Switching was confirmed to originate from local pump-induced heating of the SESAM by observing the laser going through identical regime switching when the chip temperature of the 'unpumped' SESAM was raised by ∼20°C.",
keywords = "femtosecond, forsterite, GaInAsN, laser, mode-locking, regime switching, SESAM, semiconductor lasers, quantum wells",
author = "Walsh, {D. A.} and Crombie, {C. E.} and W. Sibbett and Brown, {C. T. A.} and Savitski, {V. G.} and D. Burns and S. Calvez",
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month = "6",
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doi = "10.1117/12.922340",
language = "English",
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Walsh, DA, Crombie, CE, Sibbett, W, Brown, CTA, Savitski, VG, Burns, D & Calvez, S 2012, Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr 4+:Forsterite laser. in Laser Sources and Applications. vol. 8433, 84330G, Laser Sources and Applications, Brussels, Belgium, 16/04/12. https://doi.org/10.1117/12.922340

Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr 4+:Forsterite laser. / Walsh, D. A. ; Crombie, C. E.; Sibbett, W.; Brown, C. T. A.; Savitski, V. G.; Burns, D.; Calvez, S.

Laser Sources and Applications. Vol. 8433 2012. 84330G.

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

TY - GEN

T1 - Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr 4+:Forsterite laser

AU - Walsh, D. A.

AU - Crombie, C. E.

AU - Sibbett, W.

AU - Brown, C. T. A.

AU - Savitski, V. G.

AU - Burns, D.

AU - Calvez, S.

PY - 2012/6/13

Y1 - 2012/6/13

N2 - The ability to control the temporal output from a femtosecond laser can enable the same laser to be used for multiple functions, for example, the laser used in an optical tweezers system could be used as a constant-intensity source to trap a biological cell and then be temporarily switched to mode-locked operation to effect photoporation. Here, we report the rapid switching of a Cr 4+:forsterite laser between mode-locked and unmode-locked continuous wave (CW) regimes via the optical pumping of an intracavity SESAM element. Mode-locking of the laser was initiated by an intracavity quantum well (GaInAsN) SESAM having an anti-resonant design (ΔR∼0.3%, ?PL∼1310nm) that yielded transformlimited 89fs pulses centered around 1296nm with a repetition rate of 162MHz at an average power of 64mW. Upon excitation of the SESAM with 600mW of extra-cavity power from an 808nm semiconductor diode laser, switching could be induced between the unmode-locked and mode-locked regimes. Transitions free of Q-switching or relaxation oscillations were observed with <200μs switching times for both for the initiation and cessation of mode-locking. Periods of mode-locked operation of custom duration could be produced by appropriate control of the SESAM pump diode enabling the generation of bursts of pulses as short as 400μs. Switching was confirmed to originate from local pump-induced heating of the SESAM by observing the laser going through identical regime switching when the chip temperature of the 'unpumped' SESAM was raised by ∼20°C.

AB - The ability to control the temporal output from a femtosecond laser can enable the same laser to be used for multiple functions, for example, the laser used in an optical tweezers system could be used as a constant-intensity source to trap a biological cell and then be temporarily switched to mode-locked operation to effect photoporation. Here, we report the rapid switching of a Cr 4+:forsterite laser between mode-locked and unmode-locked continuous wave (CW) regimes via the optical pumping of an intracavity SESAM element. Mode-locking of the laser was initiated by an intracavity quantum well (GaInAsN) SESAM having an anti-resonant design (ΔR∼0.3%, ?PL∼1310nm) that yielded transformlimited 89fs pulses centered around 1296nm with a repetition rate of 162MHz at an average power of 64mW. Upon excitation of the SESAM with 600mW of extra-cavity power from an 808nm semiconductor diode laser, switching could be induced between the unmode-locked and mode-locked regimes. Transitions free of Q-switching or relaxation oscillations were observed with <200μs switching times for both for the initiation and cessation of mode-locking. Periods of mode-locked operation of custom duration could be produced by appropriate control of the SESAM pump diode enabling the generation of bursts of pulses as short as 400μs. Switching was confirmed to originate from local pump-induced heating of the SESAM by observing the laser going through identical regime switching when the chip temperature of the 'unpumped' SESAM was raised by ∼20°C.

KW - femtosecond

KW - forsterite

KW - GaInAsN

KW - laser

KW - mode-locking

KW - regime switching

KW - SESAM

KW - semiconductor lasers

KW - quantum wells

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U2 - 10.1117/12.922340

DO - 10.1117/12.922340

M3 - Conference contribution book

SN - 9780819491251

VL - 8433

BT - Laser Sources and Applications

ER -

Walsh DA, Crombie CE, Sibbett W, Brown CTA, Savitski VG, Burns D et al. Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr 4+:Forsterite laser. In Laser Sources and Applications. Vol. 8433. 2012. 84330G https://doi.org/10.1117/12.922340