Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userAll-PM Divided Pulse Fiber Oscillator Mode-locked with the Optical Kerr-effect
384
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
In this letter, we investigate a Yb-doped mode-locked fiber oscillator that uses coherent pulse division and recombination to avoid excessive nonlinear phase shifts. The mode-locking mechanism of the laser is based on the accumulation of a differential nonlinear phase between orthogonal polarization modes in the polarization-maintaining fiber segment. The inserted coherent pulse divider, based on YVO4-crystals rotated successively by 45{deg}, enables stable and undistorted mode-locked steady-states. The output pulse energy is increased from 89 pJ in the non-divided operation by ~6.5 dB to more than 400 pJ with three divisions. Measurements of the amplitude-fluctuations reveal a simultaneous broadband reduction of up to ~9 dB in the frequency range from 10 kHz to 2MHz.
rate research
Read More
We demonstrate sub-100-attosecond timing jitter optical pulse trains generated from free-running, 77.6-MHz repetition-rate, mode-locked Er-fiber lasers. At -0.002(pm0.001) ps2 net cavity dispersion, the rms timing jitter is 70 as (224 as) integrated from 10 kHz (1 kHz) to 38.8 MHz offset frequency, when measured by a 24-as-resolution balanced optical cross-correlator. To our knowledge, this result corresponds to the lowest rms timing jitter measured from any mode-locked fiber lasers so far. The measured result also agrees fairly well with the Namiki-Haus analytic model of quantum-limited timing jitter in stretched-pulse fiber lasers.
By identifying the similarities between the coupled-wave equations and the parametrically driven nonlinear Schrodinger equation, we unveil the existence condition of the quadratic soliton mode-locked degenerate optical parametric oscillator in the previously unexplored parameter space of near-zero group velocity mismatch. We study the nature of the quadratic solitons and divide their dynamics into two distinctive branches depending on the system parameters. We find the nonlinear interaction between the resonant pump and signal results in phenomena that resemble the dispersive two-photon absorption and the dispersive Kerr effect. Origin of the quadratic soliton perturbation is identified and strategy to mitigate its detrimental effect is developed. Terahertz comb bandwidth and femtosecond pulse duration are attainable in an example periodically poled lithium niobate waveguide resonator in the short-wave infrared and an example orientation-patterned gallium arsenide free-space cavity in the long-wave infrared. The quadratic soliton mode-locking principle can be extended to other material platforms, making it a competitive ultrashort pulse and broadband comb source architecture at the mid-infrared.
Lasers based on Cr$^{2+}$-doped II-VI material, often known as the Ti:Sapphire of the mid-infrared, can directly provide few-cycle pulses with super-octave-spanning spectra, and serve as efficient drivers for generating broadband mid-infrared radiation. It is expected that the wider adoption of this technology benefits from more compact and cost-effective embodiments. Here, we report the first directly diode-pumped, Kerr-lens mode-locked Cr$^{2+}$-doped II-VI oscillator pumped by a single InP diode, providing average powers of over 500 mW and pulse durations of 45 fs - shorter than six optical cycles at 2.4 $mu$m. These correspond to a sixty-fold increase in peak power compared to the previous diode-pumped record, and are at similar levels with respect to more mature fiber-pumped oscillators. The diode-pumped femtosecond oscillator presented here constitutes a key step towards a more accessible alternative to synchrotron-like infrared radiation, and is expected to accelerate research in laser spectroscopy and ultrafast infrared optics.
Ultrafast transient phenomena are the most important research field in nonlinear systems, and the mode-locking fiber laser provides an excellent research platform for ultrafast transient phenomena. We report on the experimental observation of multi-soliton asynchronous buildup dynamics in all-polarization-maintaining mode-locked fiber laser. The build-up dynamics display several novel features. The different solitons in multi-soliton generation are produced asynchronously instead of simultaneously. Solitons generated at different time have different propagation speeds at metastable state and same speeds at stable state, indicating that different solitons have different energy at metastable state. The intra-cavity energy exhibits quantization property with respect to the build-up process. A proportion of background pulse vanished with respect to the birth of new pulse, which shows the jungle law in fiber laser system. The buildup dynamics may benefit the research of ultrafast pulse generation, interaction, regulation, energy improvement, and stability improvement.
A power enhancement optical cavity is a compelling means of realizing a pulsed laser with a high peak power and high repetition frequency, which is not feasible using a simple amplifier scheme. However, a precise feedback system is necessary for maintaining the narrow resonance condition of the optical cavity; this has become a major technical issue in developing such cavities. We have developed a new approach that does not require any active feedback system, by placing the cavity in the outer loop of a laser amplifier. We report on the first demonstration of a mode-locked pulse oscillation using the new system.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
