Mid-IR photothermal imaging with a compact ultrafast fiber probe laser

A mid-IR photothermal imaging system is presented that features an integrated ultrafast erbium-doped fiber probe laser for the first time. With a mid-IR tunable quantum cascade laser (QCL) as the pump laser, vibrational molecular modes are excited and the thermally-induced changes in the refractive index are measured with a probe laser. The custom-built, all-fiber ultrafast probe laser at telecommunication wavelengths is compact, robust and thus an attractive source compared to bulky and alignment sensitive Ti:sapphire probe lasers. We present photothermal spectra and images with good contrast for a liquid crystal sample, demonstrating highly sensitive, label-free photothermal microscopy with a mode-locked fiber probe laser.

[1]  Franz X Kärtner,et al.  Compact, stable 1 GHz femtosecond Er-doped fiber lasers. , 2010, Applied optics.

[2]  Mustafa Yorulmaz,et al.  Detection limits in photothermal microscopy , 2010 .

[3]  F. Capasso,et al.  Quantum cascade lasers , 1997, Conference Digest. 2000 Conference on Lasers and Electro-Optics Europe (Cat. No.00TH8505).

[4]  S. Erramilli,et al.  Mid-IR photothermal spectroscopy with an integrated fiber probe laser , 2014, 2014 Conference on Lasers and Electro-Optics (CLEO) - Laser Science to Photonic Applications.

[5]  A. C. Albrecht,et al.  Thermal lens technique: a new method of absorption spectroscopy. , 1976, Science.

[6]  Stephen E. Bialkowski,et al.  Photothermal spectroscopy methods for chemical analysis , 1995 .

[7]  H. Haus.  Theory of mode locking with a slow saturable absorber , 1975 .

[8]  D. Choquet,et al.  Single metallic nanoparticle imaging for protein detection in cells , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[9]  Ursula Keller,et al.  Soliton mode-locking with saturable absorbers , 1996 .

[10]  Thomas Thundat,et al.  Pump–probe photothermal spectroscopy using quantum cascade lasers , 2012 .

[11]  Vladimir P. Zharov,et al.  Ultrasharp nonlinear photothermal and photoacoustic resonances and holes beyond the spectral limit , 2011, Nature photonics.

[12]  Paul V. Ruijgrok,et al.  Room-Temperature Detection of a Single Molecule’s Absorption by Photothermal Contrast , 2010, Science.

[13]  J. Faist,et al.  Quantum Cascade Laser , 1994, Science.

[14]  S. Diddams,et al.  Exploiting shot noise correlations in the photodetection of ultrashort optical pulse trains , 2013, 1302.6206.

[15]  Jerome Mertz,et al.  Nonlinear Midinfrared Photothermal Spectroscopy Using Zharov Splitting and Quantum Cascade Lasers , 2014, ACS photonics.

[16]  Rüdiger Paschotta,et al.  Passive mode locking with slow saturable absorbers , 2001 .

[17]  Vladimir Liberman,et al.  Mid-infrared photothermal heterodyne spectroscopy in a liquid crystal using a quantum cascade laser. , 2012, Applied physics letters.

[18]  Gerhard A Blab,et al.  Label-free optical imaging of mitochondria in live cells. , 2007, Optics express.

[19]  Gwyn P. Williams,et al.  Infrared synchrotron radiation programs at the National Synchrotron Light Source , 1998 .

[20]  Wei Min,et al.  Label-free imaging of heme proteins with two-photon excited photothermal lens microscopy , 2010 .