Coherent Generation of Broadband Pulsed Light in the SWIR and MWIR using an

All Polarization-Maintaining Fiber Frequency Comb Source

H. HOOGLAND, M. ENGELBRECHT, C. McRAVEN, R. HOLZWARTHMenlo Systems, GmbH, Martinsried, Germany

A. THAI, D. SÁNCHEZ, S. L. COUSIN, M. HEMMER, M. BAUDISCHICFO - Institut de Ciències Fotòniques, Barcelona, Spain

K. ZAWILSKI, P. G. SCHUNEMANNBAE Systems, Nashua, NH, USA

J. BIEGERTICREA - Instituciò Catalana de Recerca i Estudis Avançats, Barcelona, Spain.

Frequency Comb Technology

Frequency Domain

Single mode:

2 modes:

4 modes:

10 modes:

Time Domain

Laser gain bandwidth

frequency

Inte

nsity

Cavity longitudinal mode structure

frequencyIn

tens

ity

frequency

Inte

nsity

Laser output spectrum

Figure adapted from Wikipedia, Mode-locking

Frequency comb technology

• Two radio frequencies→ Repetition rate

frequency, → Offset frequency,

• Radio frequencies are easily linked to atomic time standard

• Optical frequencies are directly linked to time standard

𝜔𝑛=𝑛𝜔𝑟+𝜔0

𝜔0

𝜔𝑟

Self-referenced frequency comb

• Repetition rate frequency is stabilized by cavity length

• Offset frequency can be measured directly and stabilized by controlling cavity dispersion

2 (𝑛𝜔𝑟+𝜔0 )− (2𝑛𝜔𝑟+𝜔0 )=𝜔0

Phys. Rev. Lett. 84, 5102 (2000)Phys. Rev. Lett. 85, 2264 (2000)

Frequency Comb Applications

• Clocks– Direct RF to Optical Frequency link

• Stabilization for STIRAP – Weak transitions requiring high coherence

• Laser ranging (LIDAR)• Remote chemical-sensing

Frequency Comb Applications

• Calibration of Spectrometers– HARPS – ~ 1 cm/s

HARPS www.eso.org

fiber A

fiber B

fiber Afiber B

Monolithic connection

Image: ESO press release 2012

Frequency Comb Applications

• Spectroscopy– Time-resolved (TRFCS) – MH08– Ultrafast transient absorption – MH14– Precision absorption – MK11, TB06, TJ05– Dual comb – TJ03, TJ04– Direct – RD08, TI09– Velocity Modulation (VMS) – TG15, FA01

Spectroscopy with combs

http://structureandfunction.wordpress.com/2013/02/05/ir-spectroscopy/

• Have previously demonstrated a comb at 3 μm• 2 color, 2 arm MOPA

• Direct production with difference frequency generation (DFG)

• Frequency comb direct generation limited to Yb, Er, Ti:Sapph, etc.

• Would like to extend to NIR and further

2.03 micron comb seed source

Adapted fromOpt. Express 21, 31390 (2013)

2.03 micron comb seed source

Opt. Express 21, 31390 (2013)

• 2.03 μm• 128 fs pulse width• 110 mW

6.5 micron comb schematic

2 micron compressor

• Most materials have anamolous dispersion

• Martinez-type compressor

• Pulse lengths are 128 fs

DFG with CdSiP2

Phase matching map CdSiP2

a

Opticalaxis

q

pk

iksk

6.5 micron comb generation

Conclusion

• Broadband 2 μm seed source• 100 MHz, 128 fs, 110 mW

• Broadband 6.5 μm comb generation using DFG in CdSiP2

• 100 MHz, 50 fs, 8.5 mW

Thank you for listening!