Semiconductor Devices for Control of Laser Dynamics

用于控制激光动力学的半导体器件

• 批准号: 0217358
• 负责人: Franz Kaertner
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0217358&HistoricalAwards=false
• 关键词: Semiconductor; Devices; Control; Laser; Dynamics

For over a decade semiconductor saturable absorbers have been used very successfully in laboratories to modelock a variety of solid-state and fiber lasers. In this project, two new semiconductor devices for control of laser dynamics shall be investigated. The first device is an extension of the conventional semiconductor saturable absorber mirror used for modelocking of lasers by integrating it with an additional optically controllable modulator, for example by free carrier absorption. Even if the laser does not Q-switch, the absorber has to be saturated strongly, i.e. depending on the laser design by even more than ten times the saturation energy, to suppress this undesired Q-switching. However, such operation puts a heavy thermal load on the absorber, which reduces its lifetime. Therefore, the first goal of this proposal is to demonstrate absorbers that do not only control the mode locking but in addition the Q-switching of the laser. Such a device is able to suppress the undesired Q-switching, which often occurs in saturable absorber modelocked lasers and greatly reduces the life time of the absorber. With these absorbers a laser system can be operated in the continuous or Q-switched mode-locked regime independent of its other laser parameters such as pump power, repetition rate, output power, mode volume, upper-state lifetime, etc. In this project, the device will be applied to modelocking of high-repetition rate lasers. The second goal of this research project is to search for entirely novel control elements, i.e. semiconductor devices, that are able to detect the absolute optical phase of the pulses directly from the laser output. Such devices allow for phase control of few-cycle laser pulses and related quantities to which the absolute optical phase is ultra-sensitive, such as the intracavity pulse energy. Specifically, we want to investigate whether the recently discovered carrier-wave rabi-flopping in GaAs, which should also occur in other material systems, can be used to construct an optical phase detector. The improvement in control of solid-state laser dynamics by the envisioned devices will enable a new generation of more compact, stable and reliable laser sources with extended parameter ranges such as higher repetition rates and higher power handling capabilities. In addition, these devices will lead to a completely new generation of few-cycle laser sources, in which the absolute optical phase of the laser pulse directly emitted from the oscillator can be controlled. This has a broad range of applications in frequency metrology and strong-field ultrafast laser physics. The project is only possible because of the close cooperation between groups, which provide the know-how in material science necessary for device fabrication and groups that are able to characterize and test the devices in advanced laser systems.

十多年来，半导体可饱和吸收器已在实验室中非常成功地用于模拟各种固态和光纤激光器。 在该项目中，将研究两种用于控制激光动力学的新型半导体器件。 第一个器件是用于激光器锁模的传统半导体可饱和吸收镜的扩展，通过将其与附加的光学可控调制器集成，例如通过自由载流子吸收。即使激光器没有 Q 开关，吸收体也必须强烈饱和，即取决于激光器设计，饱和能量甚至超过饱和能量的十倍，以抑制这种不希望的 Q 开关。 然而，这种操作会给吸收器带来很大的热负荷，从而缩短其使用寿命。 因此，该提案的首要目标是证明吸收器不仅可以控制锁模，还可以控制激光器的 Q 开关。 这种器件能够抑制不需要的调Q，这种调Q经常发生在可饱和吸收体锁模激光器中，并大大缩短吸收体的使用寿命。借助这些吸收器，激光系统可以在连续或 Q 开关锁模状态下运行，独立于其他激光参数，如泵浦功率、重复率、输出功率、模式体积、上态寿命等。在该项目中，该装置将应用于高重复率激光器的锁模。该研究项目的第二个目标是寻找全新的控制元件，即半导体器件，能够直接从激光输出检测脉冲的绝对光学相位。 此类设备允许对少周期激光脉冲和绝对光学相位超敏感的相关量（例如腔内脉冲能量）进行相位控制。具体来说，我们想研究最近在 GaAs 中发现的载波拉比跳变（其他材料系统中也应该出现）是否可以用于构造光学相位检测器。所设想的设备对固态激光动力学控制的改进将使新一代更紧凑、稳定和可靠的激光源具有扩展的参数范围，例如更高的重复率和更高的功率处理能力。 此外，这些设备将带来全新一代的少周期激光源，其中可以控制直接从振荡器发射的激光脉冲的绝对光学相位。 这在频率计量和强场超快激光物理中具有广泛的应用。 该项目之所以成为可能，是因为各小组之间的密切合作，这些小组提供了设备制造所需的材料科学专业知识，而各小组能够在先进激光系统中表征和测试设备。