High-power ultrafast Yb:fiber laser frequency combs using commercially available components and basic fiber tools

Abstract

We present a detailed description of the design, construction, and performance of high-power ultrafast Yb:fiber laser frequency combs in operation in our laboratory. We discuss two such laser systems: an 87 MHz, 9 W, 85 fs laser operating at 1060 nm and an 87 MHz, 80 W, 155 fs laser operating at 1035 nm. Both are constructed using low-cost, commercially available components, and can be assembled using only basic tools for cleaving and splicing single-mode fibers. We describe practical methods for achieving and characterizing low-noise single-pulse operation and long-term stability from Yb:fiber oscillators based on nonlinear polarization evolution. Stabilization of the combs using a variety of transducers, including a new method for tuning the carrier-envelope offset frequency, is discussed. High average power is achieved through chirped-pulse amplification in simple fiber amplifiers based on double-clad photonic crystal fibers. We describe the use of these combs in several applications, including ultrasensitive femtosecond time-resolved spectroscopy and cavity-enhanced high-order harmonic generation. C 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license

Cavity-enhanced ultrafast two-dimensional spectroscopy using higher order modes

“…In conclusion, we have described methods to perform passively amplified 2D spectroscopy experiments using a frequency comb laser and optical cavities. As we have demonstrated for transient absorption spectroscopy in both isolated molecules [15] and clusters [52], a large sensitivity improvement of several orders of magnitude is expected, enabling 2D spectroscopy in dilute molecular beams. Additionally, in the one cavity scheme, the pump-probe spatial overlap factors (equation (11)) relating the absolute size of the signal to strength of the molecule's nonlinear polarization can be known precisely, enabling greater quantification of 2D spectroscopy signals for fundamental studies or analytical chemistry applications.…”

Tunable visible frequency combs from a Yb-fiber-laser-pumped optical parametric oscillator

“…The second is that actuation on the non-resonant SPOPO-generated comb via the phase of the pump does not suffer a low-pass filter due to the SPOPO cavity. This enables the use of high-bandwidth transducers, such as EOMs, in the pump comb's modelocked laser cavity [43,58] to be used to control the phase of the non-resonant comb (in our case the idler) of the OPO without needing to consider the SPOPO cavity linewidth in the design. For our SPOPO, with ∼ 2.7 MHz linewidth, the SPOPO cavity would not impose a significant low-pass filter in any event, but this point is important for SPOPOs that use higher cavity finesses to achieve low pump-power thresholds for oscillation [59].…”

“…The Er:fiber comb is shifted to 1.07 µm using a combination of a nonlinear Er-doped fiber amplifier and propagation in a short HNLF in similar manner to Maser et al [42]. The shifted comb is then amplified in a large-mode area photonic crystal fiber amplifier previously described in [43]. After the compressor, the pulses are 120 fs long with a pulse energy of 115 nJ at a repetition rate of 100 MHz.…”

Ultrafast extreme ultraviolet photoemission without space charge

“…A home-built 80 W, 155 fs frequency comb laser with a repetition rate of 88 MHz and a center wavelength of 1.035  μ m ( hν  = 1.2 eV) is passively amplified in a 6 mirror enhancement cavity with a 1% transmission input coupler and a finesse of $\mathcal{F}>560$. We have described the laser in detail previously 44 . The laser is locked to the cavity using a two-point Pound-Drever-Hall lock as described in Refs.…”

“…6(b) gives a FWHM of 181 fs. The pump laser pulse duration at the sample position was not independently measured for this experiment, but at the output of the laser the pulse duration was measured to be 165 ± 10 fs and optimal compression gives 155 fs 44 . Taking the lowest possible value of the laser pulse duration then gives a conservative upper limit for the XUV pulse duration at the sample of $\sqrt{{(181\hspace{0.17em}\text{fs})}^2-{(155\hspace{0.17em}\text{fs})}^2}=93\hspace{0.17em}\text{fs}$.…”