K. Li, A. Yao, N. J. Copner, C. B. E. Gawith, I. G. Knight, H. Pfeiffer, and B. Musk
A compact green laser of 1.3 W output at 534.7 nm is generated by intracavity frequency doubling (ICFD) of a 49 edge-emitter laser bar using a MgO-doped (PPLN) bulk crystal. The measured M2 values of green beam are 12.1 and 2.9 along the slow and fast axes, respectively. To our knowledge, this is the first demonstration of the ICFD of multi-edge-emitters laser bar.
Read paper in fullShare article
K. Li, N. Copner, C. B. E. Gawith and I. G. Knight
532nm green light source of 1.2W output is generated by intra-cavity frequency doubling (ICFD) of a multi-edge-emitter laser bar using a MgO-doped periodically poled lithium niobate (MgO:PPLN) bulk crystal. The measured M2 values of green beam are 11.9 and 2.6 along the x- and y-axes respectively. To our knowledge this is the first demonstration of the ICFD of a multi-edge-emitter laser bar.
Read paper in fullShare article
M. Zhou, B. X. Yan, G. Bao, Y. Zhang, C. B. E. Gawith, D. D. Wang, Y. Qi and Y. Bi
Intracavity second-harmonic generation of 1.56 and 1.52 W continuous-wave 532 nm green laser radiation was obtained by quasi-phase matching in periodically-poled MgO:LiNbO3 (MgO:PPLN) crystals with lengths of 2 and 1 mm, respectively. The maximum optical-to-optical efficiency achieved was 52%. The intracavity temperature bandwidth was 15 and 12°C for 1 mm crystal and 2 mm crystal, respectively.
Read paper in fullShare article
S. Koke, C. Grebing, H. Frei, A. Anderson, A. Assion and G. Steinmeyer
Carrier-envelope phase stabilization has opened an avenue towards achieving frequency metrology with unprecedented precision and optical pulse generation on the previously inaccessible attosecond timescale. Recently, sub-100-as pulsegeneration has been demonstrated, approaching the timescale of the fastest transients in atomic physics. However, further progress in attophysics appears to be limited by the performance of the traditional feedback approach used for carrier-envelope phase stabilization. Here, we demonstrate a conceptually different self-referenced feed-forward approach to phase stabilization. This approach requires no complicated locking electronics, does not compromise laser performance, and is demonstrated with 12-as residual timing jitter, which is below the atomic unit of time. This surpasses the precision of previous methods by more than a factor of five and has potential for resolving even the fastest transients in atomic or molecular physics. Such shot-noise-limited comb synthesis may also simplify progress in current research in frequency metrology.
Read paper in fullShare article
R. Selm, M. Winterhalder, A. Zumbusch, G. Krauss, T. Hanke, A. Sell, and A. Leitenstorfer
We demonstrate a scheme for efficient coherent anti-Stokes Raman scattering (CARS) microscopy free of nonresonant background. Our method is based on a compact Er:fiber laser source. Impulsive excitation of molecular resonances is achieved by an 11 fs pulse at 1210 nm. Broadband excitation gives access to molecular resonances from 0 cm-1 up to 4000 cm-1. Time-delayed narrowband probing at 775 nm enables sensitive and high-speed spectral detection of the CARS signal free of nonresonant background with a resolution of 10cm-1.
Read paper in fullShare article
K. Li, H. Wang, N. J. Copner, C. B. E. Gawith, I. G. Knight, H.-U. Pfeiffer, B. Musk, and G. Moss
A compact blue laser was generated by intracavity frequency doubling based on quasi-phase-matched second harmonic generation (SHG) in a MgO-doped periodically poled lithium niobate bulk crystal. A 49 single-transversemode edge-emitters laser bar with antireflective coating was used as a pump source. An optical output power of 1:2W SHG of blue lights at 465nm is generated at 45A injection current, equivalent to an overall wall-plug efficiency of 1.33%.
Read paper in fullShare article
S. Koke, A. Anderson, H. Frei, A. Assion and G. Steinmeyer
The noise performance of a feed-forward scheme for carrier-envelope phase stabilization is discussed. This scheme uses an acousto-optic frequency shifter to directly correct for fluctuations of the carrier-envelope phase in a pulse train emitted by a mode-locked laser without manipulating the intracavity dispersion. Generation of zero-offset frequency combs is demonstrated. Furthermore, it is shown that pump laser noise has only a minor effect on the achievable performance. Limited only by the travel time of the acoustic wave in the shifter, pump laser noise can be corrected up to near-megahertz frequencies, which yields superior noise performance compared to traditional feedback operation. Residual phase jitters down to 45mrad are experimentally verified.
Read paper in fullShare article
M. Laroche, C. Bartolacci, B. Cadier, H. Gilles, S. Girard, L. Lablonde, and T. Robin
Pulsed blue light at 489nm has been generated by second-harmonic-generation of a nanosecond pulsed master oscillator power amplifier system based on a short Yb3+ doped single-mode fiber amplifier at 978nm and an external-cavity diode laser as seed source. The Yb3+-doped fiber was core-pumped by a W type Nd3+ doped doubleclad fiber laser operating on the transition near 930nm (4F3/2 → 4I9/2). 520mW of average power was generated at 489nm using a periodically poled MgO:LiNbO3, corresponding to a conversion efficiency of 34%.
Read paper in fullShare article
L. Abrardi, T. Feurer
We present a hybrid laser system based on all-fiber amplification of a gain-switched laser diode. The diode emits low energy pulses with several tens of picoseconds pulse duration at a wavelength of 1550 nm and a repetition rate of 1 MHz. The three-stage fiber amplifier reaches an overall gain of 55 dB boosting the pulse energy to 0.48 μJ. Much care is taken to preserve an almost bandwidth limited pulse with a spectral width of 0.1 nm and negligible spectral broadening due to nonlinearities. The laser system has been designed such that two or more can be electronically synchronized with the aim to combine them for exploring frequency mixing scenarios. Here, we report first cross-correlation measurements of two synchronized laser systems and present a method to characterize the relative timing-jitter.
Read paper in fullShare article
S. S. Sané, S. Bennetts, J. E. Debs, C. C. N. Kuhn, G. D. McDonald, P. A. Altin, J. D. Close, and N. P. Robins
We present a narrow linewidth continuous laser source with over 11 W output power at 780 nm, based on single-pass frequency doubling of an amplified 1560 nm fibre laser with 36% efficiency. This source offers a combination of high power, simplicity, mode quality and stability. Without any active stabilization, the linewidth is measured to be below 10 kHz. The fibre seed is tunable over 60 GHz, which allows access to the D2 transitions in 87Rb and 85Rb, providing a viable high-power source for laser cooling as well as for large-momentum-transfer beamsplitters in atom interferometry. Sources of this type will pave the way for a new generation of high flux, high duty-cycle degenerate quantum gas experiments.
Read paper in fullShare article