Shim Sang-Hee, Strasfeld David B, Fulmer Eric C, Zanni Martin T
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706-1396, USA.
Opt Lett. 2006 Mar 15;31(6):838-40. doi: 10.1364/ol.31.000838.
Pulse shaping directly in the mid-IR is accomplished by using a germanium acousto-optic modulator (Ge AOM) capable of programmable phase and amplitude modulation for IR light between 2 and 18 microm. Shaped waveforms centered at 4.9 microm are demonstrated in both the frequency and the time domains. With a 50% throughput efficiency, the Ge AOM can generate much more intense pulses with higher resolution than can indirect shaping methods. Furthermore, the phase stability of the shaped pulse proved sufficient for cross correlation with unshaped mid-IR pulses. Thus, phase- and amplitude-tailored pulses can now be readily incorporated into phase-sensitive experiments, such as heterodyned 2D IR spectroscopy.
通过使用一种锗声光调制器（Ge AOM），可在中红外波段直接实现脉冲整形，该调制器能够对2至18微米的红外光进行可编程的相位和幅度调制。在频域和时域均展示了以4.9微米为中心的整形波形。锗声光调制器具有50%的通量效率，与间接整形方法相比，它能够产生强度更高、分辨率更高的脉冲。此外，整形脉冲的相位稳定性足以与未整形的中红外脉冲进行互相关。因此，相位和幅度定制的脉冲现在可以很容易地应用于相敏实验，如外差二维红外光谱。
