Semiconductor Laser with OpticaI Feedback

Output power time series from an edge-emitting, multiple quantum well 830nm semiconductor laser subject to optical feedback. Time series recorded for different combinations of optical feedback level and laser injection current. Detection bandwidth 4 GHz and sampling rate 20 GSa/s.Full details here http://research.science.mq.edu.au/photonics-dynamical-systems/our-research/semiconductor-lasers-with-optical-feedback/bulk-optic-4-ghz-bw/This data set was recorded from an experimental semiconductor laser subject to optical feedback on 13/08/12. Laser wavelength ~ 830nm. External cavity round trip time 4.5ns. During the experiment, 2 system parameters were varied: the optical feedback level and laser injection current. - Optical feedback was varied by changing the RF power to an acousto-optic modulator (AOM) which varies the amount of laser power transmitted in the 0th order beam. A voltage between 0V-1V corresponds to maximum transmission (0V) and minimum transmission (1V). The actual power transmitted by the AOM is not a linear relationship with voltage. Relative feedback level can be approximated from the reduction in laser threshold. - Laser injection is controlled by directly varying the current supply to the device (Profile ITC510 Laser Diode Combi-controller). Laser was held at a constant 25C. The dataset contains 88,101 files containing output power time series recorded from the laser using a fast photodiode (Discovery Semiconductors DCS30S 22GHz) and 4GHz realtime oscilloscope (Agilent 54854A) for different settings of: - Injection (251 values = 45mA to 70mA in 0.1mA steps) - Feedback (351 values from 0.45V to 0.8V in 0.001V steps) The filenames consist of the AOM and INJ values at which the data was recorded: e.g. AOM_0.642V_INJ_45.2mA.h5 : feedback = 0.642 V, injection = 45 mA Each hdf5 file consist of a single dataset called 'TimeSeries'. This contains a time series of amplitude values measured as the voltage across the 50ohm oscilloscope input. Time series were sampled at 20GSamples/s (50ps per data point) and contain 20,000pts for a total record length of 1microsecond.ReferenceJ. P. Toomey and D. M. Kane, 'Mapping the dynamic complexity of a semiconductor laser with optical feedback using permutation entropy,' Optics Express 22 (2), 1713-1725 (2014).

本数据集收录了带光反馈（optical feedback）的边发射型多量子阱830nm半导体激光器的输出功率时间序列。时间序列采集自不同光反馈强度与激光注入电流的组合工况，实验探测带宽为4 GHz，采样率为20 GSa/s。完整实验细节可访问以下链接查看：http://research.science.mq.edu.au/photonics-dynamical-systems/our-research/semiconductor-lasers-with-optical-feedback/bulk-optic-4-ghz-bw/

本数据集采集自2012年8月13日的光反馈半导体激光实验平台，激光器波长约830nm，外腔往返时间为4.5ns。实验中共调控两个系统参数：光反馈强度与激光注入电流。

光反馈强度通过改变声光调制器（acousto-optic modulator, AOM）的射频功率实现调控，该器件可调节0级衍射光束的透射激光功率。输入电压范围为0V至1V，其中0V对应最大透射功率，1V对应最小透射功率，但声光调制器的透射功率与输入电压并非线性关系，相对反馈强度可通过激光阈值的降低程度近似估算。

激光注入电流通过直接调节激光器供电电源（型号为ITC510激光二极管组合控制器）实现调控，实验过程中激光器温度维持恒定25℃。

本数据集共包含88101个数据文件，均为采用快速光电探测器（fast photodiode，型号为Discovery Semiconductors DCS30S 22GHz）与4GHz实时示波器（realtime oscilloscope，型号为Agilent 54854A）采集得到的激光输出功率时间序列，对应以下两类参数的不同设置：
- 注入电流：共251个取值，范围为45mA至70mA，步长0.1mA
- 反馈电压：共351个取值，范围为0.45V至0.8V，步长0.001V

文件名包含采集时的声光调制器反馈电压与激光注入电流参数，例如`AOM_0.642V_INJ_45.2mA.h5`，对应反馈电压0.642V、注入电流45.2mA。

每个HDF5文件均包含一个名为`TimeSeries`的数据集，存储示波器50Ω输入端口上的电压幅值时间序列。时间序列采样率为20GSa/s（单个数据点间隔50ps），单条序列包含20000个数据点，总记录时长为1微秒。

参考文献：J. P. Toomey与D. M. Kane，《利用排列熵（permutation entropy）绘制带光反馈半导体激光器的动态复杂性图谱》，Optics Express 22(2), 1713-1725 (2014).