Laurain A, Myara M, Beaudoin G, Sagnes I, Garnache A
Institut d'Electronique du Sud, CNRS UMR5214, Université Montpellier 2, France.
Opt Express. 2009 Jun 8;17(12):9503-8. doi: 10.1364/oe.17.009503.
We demonstrate high power high efficiency (0:3 W) low noise single frequency operation of a compact extended-cavity surface-emitting-semiconductor-laser exhibiting a continuous tunability over 0:84 THz with high beam quality. We took advantage of thermal lens-based stability to develop a short (< 3 mm) plano-plano external cavity without any intracavity filter. The structure is optically pumped by a 1 W commercial 830 nm multimode diode laser. No heat management was required. We measured a low divergence circular TEM(00) beam at the diffraction limit (M(2) < 1:05) with a linear light polarization (> 37 dB). The side mode suppression ratio is 60 dB. The free running laser linewidth is 850 kHz limited by pump induced thermal fluctuations. Thanks to this high-Q external cavity approach, the frequency noise is low and the dynamics is in the relaxation-oscillation-free regime, exhibiting a low intensity noise, with a cutoff frequency approximately 250 MHz above which the shot noise level is reached. We show that pump properties define the cavity design and laser coherence.
我们展示了一种紧凑型外腔表面发射半导体激光器的高功率、高效率（0.3瓦）、低噪声单频运行，其具有0.84太赫兹的连续可调谐性以及高光束质量。我们利用基于热透镜的稳定性开发了一种短（<3毫米）的平-平外腔，且无任何腔内滤波器。该结构由一台1瓦的商用830纳米多模二极管激光器进行光泵浦。无需热管理。我们在衍射极限（M²<1.05）下测量到了低发散圆形TEM(00)光束，其具有线性光偏振（>37分贝）。边模抑制比为60分贝。自由运行的激光线宽受泵浦引起的热波动限制为850千赫兹。得益于这种高Q值外腔方法，频率噪声较低，并且动力学处于无弛豫振荡状态，表现出低强度噪声，其截止频率约为250兆赫兹，高于该频率则达到散粒噪声水平。我们表明，泵浦特性决定了腔的设计和激光相干性。
