Elezzabi A Y, Meyer J, Hughes M K, Johnson S R
Opt Lett. 1994 Jun 15;19(12):898-900. doi: 10.1364/ol.19.000898.
Using a GaAs layer grown by molecular-beam epitaxy at low substrate temperature as an optical semiconductor switch, we demonstrate the generation of picosecond infrared pulses at 10.6 microm. To our knowledge, this is the first time that ultrashort pulses have been generated by use of only one reflective switch. A cross-correlation method, which is used to measure the pulse width, indicates that the pulse width is ~1 ps. A 200-nm-thick, low-temperature molecular-beam-epitaxy-grown GaAs layer, acting as an ultrafast active switching element, was grown at a low temperature of 320 degrees C on a GaAs substrate and annealed at 550 degrees C. The presence of a high density of As precipitates in this material that act as fast recombination centers gives the optically injected carriers in low-temperature molecular-beam-epitaxy-grown GaAs a lifetime of 0.5 ps. We also discuss the feasibility of the extension of this technique to other mid- and far-infrared lasers.
我们使用在低衬底温度下通过分子束外延生长的砷化镓层作为光半导体开关，展示了在10.6微米波长处产生皮秒红外脉冲。据我们所知，这是首次仅使用一个反射开关产生超短脉冲。用于测量脉冲宽度的互相关方法表明，脉冲宽度约为1皮秒。一个200纳米厚、通过低温分子束外延生长的砷化镓层，作为超快有源开关元件，在320摄氏度的低温下生长在砷化镓衬底上，并在550摄氏度下退火。这种材料中存在高密度的砷沉淀，它们作为快速复合中心，使得在低温分子束外延生长的砷化镓中光注入载流子的寿命为0.5皮秒。我们还讨论了将该技术扩展到其他中红外和远红外激光器的可行性。
