In earlier work, we suggested using a curved waveguide as a quantum simulator to simulate the tunnel ionization process. Here we implemented for the first time such a simulator and tested our results against the Keldysh and bending loss ionization rates. We observed also straight rays which are reminiscent of above-threshold-ionization (ATI) electrons.
Laser induced x-ray fluorescence were observed against laser polarization ellipticity. While emission from krypton peaks at linear polarization, a signature of recollision, emission from neon shows opposite trend. We attribute it to two competing processes.
We introduce a hybrid CPA system of Yb-doped fibers and Nd:glass rods, with use of aperiodic-frequency-converter crystal around 526 nm, demonstrated ~40% efficiency, and ~40 dB pulse contrast improvement. New result with novel SLT-made-AFC yielded ~60% efficiency, both showed near full bandwidth conversion. A Neodymium:glass CPA pulse yielded record energy result of 320s μJ in 527 nm second harmonic with the LiNBO3. Additionally, new, very low-cost, robust method, based on time-space nonlinear-index self-focusing effect showed >20-dB contrast enhancement.
We demonstrate an external-cavity KGd(WO4)2 (KGW) Raman laser, pumped by an actively Q-switch Tm:YLF MOPA. The fundamental spectral line emitting at 1881 nm allowed the KGW bi-axial crystal to lase at two separate output spectral lines, 2198 and 2265 nm, depending on the seed polarization axis relative to the KGW's axis. The Tm:YLF seed was amplified using a double-pass Tm:YLF crystal based MOPA setup. After amplification, the seed achieved an output power of 9.15 W, and an energy pulse of 4.57 mJ, a pulse duration of 43 ns at a repetition rate of 2 kHz. The max output average power achieved for the 2265 nm was 1.85 W, with a pulse energy of 0.923 mJ at a repetition rate of 2 kHz implying a conversion efficiency of ~20.5%. We noticed a very low conversion efficiency of the shorter KGW spectral shift (at 2198 nm). The reason for this efficiency drop was validated to be the 2nd stokes forming and thus consuming the 1st stokes energy. In favor of the KGW inherent properties and according to the aforementioned results, this crystal appears to be suitable for power scaling as well as for improvement of the Raman conversion efficiency in this spectral range. The KGW crystal is well known for its use in shorter spectral wavelengths. To the best of our knowledge, it is the highest average power achieved by lasing in the 2 μm region using SRS with KGW.
We report a simple robust and broadly spectral-adjustable source generating near fully compressed 1053 nm 62 fs pulses directly out of a highly-nonlinear photonic crystal fiber. A dispersion-nonlinearity balance of 800 nm Ti:Sa 20 fs pulses was obtained initially by negative pre-chirping and then launching the pulses into the fibers' normal dispersion regime. Following a self-phase modulation spectral broadening, some energy that leaked below the zero dispersion point formed a soliton whose central wavelength could be tuned by Self-Frequency-Raman-Shift effect. Contrary to a common approach of power, or, fiber-length control over the shift, here we continuously varied the state of polarization, exploiting the Raman and Kerr nonlinearities responsivity for state of polarization. We obtained soliton pulses with central wavelength tuned over 150 nm, spanning from well below 1000 to over 1150 nm, of which we could select stable pulses around the 1 μm vicinity. With linewidth of > 20 nm FWHM Gaussian-like temporal-shape pulses with ∼ 62 fs duration and near flat phase structure we confirmed high quality pulse source. We believe such scheme can be used for high energy or high power glass lasers systems, such as Nd or Yb ion-doped amplifiers and systems.
Conference Committee Involvement (1)
Ultrafast Optics 2017
8 October 2017 | Jackson Hole, Wyoming, United States
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.