Mode-locked Ti: sapphire laser

Spence D E, Kean P N and Sibbett W 1991 60 fs pulse generation from a self-mode-locked Ti sapphire laser Qpt. Lett. 16 42—4... 

Figure 4.6 shows an apparatus for the fluorescence depolarization measurement. The linearly polarized excitation pulse from a mode-locked Ti-Sapphire laser illuminated a polymer brush sample through a microscope objective. The fluorescence from a specimen was collected by the same objective and input to a polarizing beam splitter to detect 7 and I by photomultipliers (PMTs). The photon signal from the PMT was fed to a time-correlated single photon counting electronics to obtain the time profiles of 7 and I simultaneously. The experimental data of the fluorescence anisotropy was fitted to a double exponential function. 

By launching femtosecond pulses from a mode-locked Ti Sapphire laser into an appropriate microstructured fiber, one can generate a supercontinuum output spanning from the blue to the near... 

P. F. Curley, A. I. Ferguson, J.G. White and W. B. Amos, Application of a femtosecond self-sustaining mode-locked Ti sapphire laser to the field of laser scanning confocal microscopy, Opt. Quant. Elec. 24, 851-859 (1992). 

Leitenstorfer, A., Furst, C., and Lauhereau, A. 1995. Widely mnahle 2-color mode-locked Ti-sapphire laser with pulse jitter of less-than -2-fs. Opt. Lett. 20 916-18. 

Figure 10.10 shows the experimental system of TE-CARS microscopy (Ichimura et al. 2004a). As similar to the TERS system (Hayazawa et al. 2000), the system mainly consists of an excitation laser, an inverted microscope, an AFM using a silver-coated probe, and a monochromator. Two mode-locked Ti sapphire lasers (pulse duration 5 picoseconds [ps] spectral band width 4 cm- repetition rate 80 MHz) are used for the excitation of CARS. The (o and (O2 beams are collinearly combined in time and space, and introduced into the microscope with an oil-immersion objective lens (NA = 1.4) focused onto the sample surface. As the z-polarized component of the... 

The apparatus used for the experiments is shown in Figure 3. The pulsed light source was a 80 MHz mode-locked Ti sapphire laser (Spectra-Physics Tsunami) (1) pumped by a continuous wave (cw) diode laser (Spectra-Physics Millennia) (2), that produced 90 fs pulses at a centre photon energy of o>=l.575 0.005 eV (787 nm). The apertures (3) were used to reset the beam direction following any drift in the laser alignment. 

The shortest directly produced optical pulses, produced by Kerr-lens mode-locked Ti-sapphire lasers, last around 3.4fs = 3.4 x 10 15s. However, the minimum pulse duration is limited by the period of the carrier frequency (which is about 2.7 fs for Ti S systems). Some advanced techniques (involving high harmonic generation with amplified fs laser pulses) can be used to produce pulses as short as 10 16s for X < 30 nm. 

Figure 5.3 shows a schematic illustration of our HRS measurement system [26-28]. A mode-locked Ti sapphire laser (Spectra-Physics, Tsunami) was used to induce HRS. Pulses of 70 fs at 790 nm with a repetition rate of 82 MHz were spectrally narrowed by a custom-made laser line filter (Optical Coatings Japan). The obtained pulse width was 14 cm FWHM with a pulse duration of 1 ps (measured by autocorrelation). These pulses were introduced into an inverted microscope system (Nikon, TE-2000) with a 36x, 0.52 N.A. reflective microscope objective or a 100 X, 1.49 N.A. oil-immersion microscope objective. Backscattered photons were collected by the same objective and filtered by dichroic mirrors (Optical Coatings Japan). Finally, HRS signals were detected by a charge-coupled camera (Princeton Instruments, PIXIS 400B) with a polychromator (ACTON, SP2500i). 

Lasers in cw mode have gc= 1 and require some orders of magnitude more average power in comparison with a mode locked Ti sapphire laser. This may result in photodestruction of the chromophore and is not desired. 

Figure 3.72. Dependence of lateral resolution and depth resolution on average power of a mode-locked Ti sapphire laser (wavelength 763 nm, 82MHz repetition, 130 fs pulse width) during TP initiated polymerization of a urethane acrylate resin. (From Ref. [575] with permission of SPIE—The International Society for Optical Engineering.)...

Figure 3.97. Schematic setup of the combination of the mode-locked Ti sapphire laser, the inverted fluorescence microscope, and the detection system. (From Ref. [112] with permission of the American Chemical Society.)...

Huang C-P, Asaki M T, Backus S, Murnane M M and Kapteyn H C 1992 17 fs pulses from a self-mode-locked Ti sapphire laser Opt. Lett. 17 1289-91... 

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