Fabry-Perot type semiconductor laser with bulk optic feedback system – 4 GHz Detection Bandwidth with Optical Spectra

The experimental setup, shown in Fig. 1, consists of a multiple quantum well 830 nm semiconductor laser (APL 830-40) which has a free-running room temperature threshold of 48.2 mA. The output beam is collimated with an 8 mm focal length aspheric lens. The beam then passes through a 50:50 cube beamsplitter and an acousto-optic modulator (G&H 23080) before being reflected from an external mirror (R = 99%). It is the zeroth order beam from the acousto-optic modulator (AOM) which is coupled back to the semiconductor laser as the delayed optical feedback. The beam splitter directs half of the output beam to a 22 GHz photodiode. The photodiode signal was recorded for 1 µs (20 kpts) on a digital oscilloscope (Agilent Infiniium 54854A DSO) with a 4 GHz real-time bandwidth at a sampling rate of 20 GSa/s to constitute a single time series for subsequent analysis. Optical spectra were captured on an Anritsu MS9710C optical spectrum analyser with 0.1nm resoltuion  The external cavity established by the external reflector has a round trip length of 135 cm (4.5 ns round trip period).

Fig. 1. Semiconductor laser with optical feedback setup
Fig. 1. Semiconductor laser with optical feedback setup

A high density data set of experimental output power time series was generated that could then be analyzed using a number of different analysis tools to generate high resolution maps. These quantify different aspects of the nonlinear dynamics at any point in the parameter space. The parameter space was injection current and the fraction of delayed optical feedback. The injection current was swept from 45 mA to 70 mA in steps of 0.1 mA and the optical feedback level was varied by adjusting the 0th order transmission of the AOM. Transmission was controlled by varying the AOM modulation input voltage from 0.2 V to 0.9 V (in 351 steps of 0.002 V), giving a total of 123,201 time series covering the operating region of interest.

 

References

[1] J. 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).

 

 

Information about the data available

Download here

This data is being provided to be used in the context of the SIEF project “Big Data Knowledge Discovery”

Any use of this data should cite the following reference:
J. 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).

Source:

Dr Joshua P Toomey
MQ Photonics Research Centre
Department of Physics and Astronomy
Macquarie University
josh.toomey@mq.edu.au

Prof Deborah M Kane
MQ Photonics Research Centre
Department of Physics and Astronomy
Macquarie University
deb.kane@mq.edu.au

Data Set Information:
This data set was recorded from an experimental semiconductor laser subject to optical feedback on 14/09/12.
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 123,201 files containing output power time series recorded from the laser using a fast photodiode (Discovery Semiconductors DCS30S 22GHz) and 4 GHz realtime oscilloscope (Agilent 54854A) and optical spectra recorded on an Anritsu MS9710C with 0.1 nm resoltuion and 1 kHz VBW for different settings of:

  • Injection (351 values = 35 mA to 70 mA in 0.1 mA steps)
  • Feedback (351 values from 0.2 V to 0.9 V in 0.002 V 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

These values are also recorded in the file attributes as ‘var1’ and ‘var2’.

Each hdf5 file consist of a 2 datasets called ‘TimeSeries’ and ‘OpticalSpectrum’.

TimeSeries 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.

OpticalSpectrum contains a single spectrum containing 1001 sample points between 825nm and 840nm.”