29 research outputs found
Polarization-Tailored Raman Frequency Conversion in Chiral Gas-Filled Hollow Core Photonic Crystal Fibers
Broadband-tunable sources of circularly-polarized light are crucial in fields
such as laser science, biomedicine and spectroscopy. Conventional sources rely
on nonlinear wavelength conversion and polarization control using standard
optical components, and are limited by the availability of suitably transparent
crystals and glasses. Although gas-filled hollow-core photonic crystal fiber
provides pressure-tunable dispersion, long well-controlled optical
path-lengths, and high Raman conversion efficiency, it is unable to preserve
circular polarization state, typically exhibiting weak linear birefringence.
Here we report a revolutionary approach based on helically-twisted hollow-core
photonic crystal fiber, which displays circular birefringence, thus robustly
maintaining circular polarization state against external perturbations. This
makes it possible to generate pure circularly-polarized Stokes and anti-Stokes
signals by rotational Raman scattering in hydrogen. The polarization state of
the frequency-shifted Raman bands can be continuously varied by tuning the gas
pressure in the vicinity of the gain suppression point. The results pave the
way to a new generation of compact and efficient fiber-based sources of
broadband light with fully-controllable polarization state.Comment: 5 pages, 4 figure
Damage-free single-mode transmission of deep-UV light in hollow-core PCF
Transmission of UV light with high beam quality and pointing stability is
desirable for many experiments in atomic, molecular and optical physics. In
particular, laser cooling and coherent manipulation of trapped ions with
transitions in the UV require stable, single-mode light delivery. Transmitting
even ~2 mW CW light at 280 nm through silica solid-core fibers has previously
been found to cause transmission degradation after just a few hours due to
optical damage. We show that photonic crystal fiber of the kagom\'e type can be
used for effectively single-mode transmission with acceptable loss and bending
sensitivity. No transmission degradation was observed even after >100 hours of
operation with 15 mW CW input power. In addition it is shown that
implementation of the fiber in a trapped ion experiment significantly increases
the coherence times of the internal state transfer due to an increase in beam
pointing stability
High average power and single-cycle pulses from a mid-IR optical parametric chirped pulse amplifier
In attosecond and strong-field physics, the acquisition of data in an acceptable time demands the combination of high peak power with high average power. We report a 21 W mid-IR optical parametric chirped pulse amplifier (OPCPA) that generates 131 mu J and 97 fs (sub-9-cycle) pulses at a 160 kHz repetition rate and at a center wavelength of 3.25 mu m. Pulse-to-pulse stability of the carrier envelope phase (CEP)-stable output is excellent with a 0.33% rms over 288 million pulses (30 min) and compression close to a single optical cycle was achieved through soliton self-compression inside a gas-filled mid-IR antiresonant-guiding photonic crystal fiber. Without any additional compression device, stable generation of 14.5 fs (1.35-optical-cycle) pulses was achieved at an average power of 9.6 W. The resulting peak power of 3.9 GW in combination with the near-single-cycle duration and intrinsic CEP stability makes our OPCPA a key-enabling technology for the next generation of extreme photonics, strong-field attosecond research, and coherent x-ray science. (C) 2017 Optical Society of Americ