Progress in Cherenkov femtosecond fiber lasers

Abstract

We review the recent developments in the field of ultrafast Cherenkov fiber lasers. Two essential properties of such laser systems – broad wavelength tunability and high efficiency of Cherenkov radiation wavelength conversion are discussed. The exceptional performance of the Cherenkov fiber laser systems are highlighted - dependent on the realization scheme, the Cherenkov lasers can generate the femtosecond output tunable across the entire visible and even the UV range, and for certain designs more than 40 % conversion efficiency from the pump to Cherenkov signal can be achieved. The femtosecond Cherenkov laser with all-fiber architecture is presented and discussed. Operating in the visible range, it delivers 100–200 fs wavelength-tunable pulses with multimilliwatt output power and exceptionally low noise figure an order of magnitude lower than the traditional wavelength tunable supercontinuum-based femtosecond sources. The applications for Cherenkov laser systems in practical biophotonics and biomedical applications, such as bio-imaging and microscopy, are discussed.

High-power frequency comb source tunable from 27 to 42 μm based on difference frequency generation pumped by an Yb-doped fiber laser

“…an Er-doped fiber laser [14][15][16]. The pump radiation for the DFG process is then provided by down-conversion of the 1.56 μm signal to the 1 μm band in a highly nonlinear fiber (HNLF) through the so-called dispersive wave (DW) generation (also referred to as Cherenkov radiation [17]). This approach benefits from the high coherence of the DW, however, the power stored in the DW is usually low [18] and an additional Yb-doped fiber amplifier in the pump branch is required to boost the power prior to frequency mixing in the crystal [15,16].…”

Megawatt peak power tunable femtosecond source based on self-phase modulation enabled spectral selection

“…Compatible with fiber technology, use of nonlinear fiber-optic methods to generate wavelength widely tunable femtosecond pulses from an ultrafast fiber laser is of particular interest. The typical methods include soliton self-frequency shift [3][4][5][6][7][8][9][10][11][12][13][14], dispersive wave generation [15][16][17][18], and four-wave mixing [19][20][21].…”

Carrier-envelope-phase-stable soliton-based pulse compression to 44 fs and ultraviolet generation at the 800 kHz repetition rate

“…4(a). DW emission has been widely exploited in both solid and hollow-core fibers for efficient and tunable frequency up-and down-conversion [25]. In HC fibers tunability from the visible down to the vacuum UV has been demonstrated at pump laser repetition rates from 1 kHz to 10 MHz [10,[26][27][28], with conversion efficiencies up to 15% [26].…”