High Energy Non - Collinear OPA A Non collinear pumping scheme of an OPA is used when the collinear approach for the OPA reaches its limits in respect to broad spectral Pulse Duration Down to 10 Femtoseconds bandwidth and / or extremely short pulses (< 20 fs). The basic principle of operation of NOPA relies on parametric amplification of chirped signal produced by supercontinuum generation in a transparent medium High Energy Visible Output possessing third order nonlinearity. The non-collinear geometry is used due to broad amplification bandwidth in the visible spectral range. Wavelength Tuning Computer Controlled geometry and the limited applicable pump energy. Typical signal pulse energy Main problem in the “classical” NOPA approach is associated with non-collinear is a few microjoules. In the TOPAS-white developed by Light Conversion, the Pulse Duration and Bandwidth control Built in Pulse Compressor output energy is enhanced by using a pump pulse with appropriate front tilt. The tilt of pump pulse is achieved by combination of a dispersive optic and a telescope. Another problem of the “classical” NOPA approach is a complex issue of Compact and stable design dispersion matching over broad wavelength range, which is necessary for generation of near- transform limited sub-30 fs pulses. This problem is usually High Output Stability solved either by optimizing pulse compressor for limited wavelength range, or by use of complex adaptive systems that also introduce significant loss for the output pulse. The TOPAS-white offers significant improvement regarding above problems. The device is a two-stage non-collinear parametric amplifier of white light continuum. The way of operation is as follows (see schematic).

Pulse-phase shaper White-light generator TOPAS-white and TOPAS-white-SH DIMENSIONS in cm (inches) Optical Layout of Topas-White A small fraction of the incoming 800 nm pulse is used to produce white light continuum in a sapphire plate. The white light beam is collimated using chromatic aberration free, low astigmatism collimator. Then the pulse is sent into a double pass negative dispersion pulse phase shaper consisting of a diffraction grating, a spherical mirror, a folding mirror and a phase mask. Dispersion of this pulse shaper is calculated in order to achieve an adapted chirp of the seed...

PERFOMANCE SPECIFICATIONS FOR ~100 fs pump pulses PUMP REQUIREMENTS_ Pulse duration (FWHM) 80 - 150 fs_ Spectral input bandwidth < 180 cm1_ Instability of pulse duration < 2% rms_ Input spatial profile_Gaussian - Hyper Gaussian SIGNAL OUTPUT (with 800 nm, 0.5 mJ pump) Tuning range Pulse energy Pulse duration, assuming Gaussian profile Energy instability (depending on the wavelength and the input Pulse bandwidth < 1.8 times transform limit OUTPUT FROM SECOND-HARMONIC GENERATOR (with 800 nm, 0.5 mJ pump) Pulse duration, assuming < 40 fs @ 325 nm (depending on the wavelength and the input Note:...

PERFOMANCE SPECIFICATIONS FOR ~35 fs pump pulses PUMP REQUIREMENTS Input wavelength Pulse energy Pulse duration (FWHM) Spectral input bandwidth Energy instability Instability of pulse duration Input spatial profile Intensity modulation 780 - 820 nm 0.2- 0.6 mJ >35 fs < 450 cm-1 < 1.0% rms < 2% rms Gaussian - Hyper Gaussian < 15% SIGNAL OUTPUT (with 800 nm, 0.5 mJ pump) Tuning range Pulse energy Pulse duration, assuming Gaussian profile Energy instability < 2.5% rms - 9% rms (depending on the wavelength and the input stability) Pulse bandwidth < 1.8 times transform limit OUTPUT FROM SECOND-HARMONIC...

LIGHT CONVERSION Typical signal pulse duration Spectral intensity Normalized Intensity PERFOMANCE DATA Signal Autocorrelations and Spectra Spectral intensity Normalized Intensity Spectral intensity Normalized Intensity Spectral intensity Normalized Intensity

-white Narrow signal spectrum mode PERFOMANCE DATA Autocorrelation measurement Gaussian fit Spectral intensity Normalized Intensity TOPAS-white-SHS spectra of second harmonic of signal Normalized Intensity LIGHT CONVERSION LTD Sauletekio av. 10 LT-10223 Vilnius Lithuania Tel.+370 5 2491830 Fax.+370 5 2698723 E-mail: [email protected] INVISIBLE & VISIBLE LASER RADIATION AVOID EYE OR SKIN EXPOSURE TO DIRECT OR SCATTERED RADIATION POWER AND WAVELENGTH DEPEND ON PUMP OPTIONS AND LASER CONFIGURATION: CLASS IV LASER PRODUCT