  We report on two types of Raman laser sources emitting in the near and middle
ultraviolet spectral ranges by the use of a solarization-resilient gas-filled
inhibited-coupling (IC) hollow-core photonic-crystal fiber (HCPCF) with record
low transmission loss (minimum of 5 dB/km at 480 nm). The first source type
emits a Raman comb generated in a hydrogen-filled HCPCF pumped by a 355 nm
wavelength microchip nanosecond pulsed laser. The generated comb lines span
from 270 nm to the near-infrared region with no less than 20 lines in the
270-400 nm wavelength range. The second type stands for the first
dual-wavelength Raman source tuned to the ozone absorption band in the
ultraviolet. Such dual-wavelength source emits at either 266 nm and 289 nm, or
266 nm and 299 nm. The relative power of the pair components is set to optimize
the sensitivity of ozone detection in differential absorption lidar (DIAL). The
source's physical package represents more than 10-fold size-reduction relative
to current DIAL lasers, thus opening new opportunities in on-field ozone
monitoring and mapping. Both Raman sources exhibit a very small footprint and
are solarization-free.
