Photonic Integrated Chip – DFB Laser with Integrated Waveguide Feedback System

This device was develped as part of the European Commission PICASSO project by M. Hamacher and colleagues at the Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institute, Berlin, Germany [1]. This is the same device as those used as transmitter/receiver pairs in a demonstration of chaotic secure communication over 100 km transmission path which achieved a bit error rate of 10-12 for bit rates up to 2.5Gb/s [2].

It consists of a 300 μm DFB laser section with an operating wavelength of 1561 nm and a measured linewidth enhancement factor of α = 3.5; a 200 μm variable optical attenuation section, which can either be forward biased for gain or reverse biased for attenuation; a 150 μm phase control section and a high reflective coating on the end facet of a 1 cm long passive waveguide section. The latter section provides the necessary optical feedback for chaotic operation. A schematic of the device is shown in Fig. 1

Fig. 1. Schematic of the PIC laser device that includes an InGaAsP DFB laser (λ = 1561 nm), a 200 μm gain/absorption section, a phase section and a 1 cm passive waveguide. Reproduced from [1].
Fig. 1. Schematic of the PIC laser device that includes an InGaAsP DFB laser (λ = 1561 nm), a 200 μm gain/absorption section, a phase section and a 1 cm passive waveguide. Reproduced from [1].

The laser output characteristics can be tuned by direct biasing of the 3 active sections. Applying a forward injection current to the DFB laser section (IDFB) provides the necessary gain for lasing. The other 2 active sections control the strength (IGAS or VGAS) and phase (IPH) of the feedback from the HR coated end facet. The laser output power dynamics were detected at the AR coated end facet of the DFB section. Experimental time series containing 80000 points were recorded on a 12GHz bandwidth real-time oscilloscope sampled at 40 GSa/s. A variety of complex dynamics can be observed over an extensive operating parameter space.

Fig. 2. (a) Map of the permutation entropy as a function of both DFB laser injection current and gain section current for a fixed phase section current = 0 mA. Observed time series outputs from different parts of the parameter space: (b) switching between CW and pulse-like output, (c) regular pulse packages, (d) broadband chaos, (e) sinusoidal oscillations and (f) CW output. After [3].
Fig. 2. (a) Map of the permutation entropy as a function of both DFB laser injection current and gain section current for a fixed phase section current = 0 mA. Observed time series outputs from different parts of the parameter space: (b) switching between CW and pulse-like output, (c) regular pulse packages, (d) broadband chaos, (e) sinusoidal oscillations and (f) CW output. After [3].

The relative complexity of the system output has been quantified using permutation entropy [3]. The results shown in Fig. 1 reveal the diverse range of outputs which are possible when operated under different conditions.

Analysis of this system has also revealed the device can transition between short-cavity and long-cavity regimes by adjustment of the relaxation oscillation frequency via appropriate biasing of the DFB section [4].

 

References

[1] A. Argyris, M. Hamacher, K. E. Chlouverakis, A. Bogris, and D. Syvridis, “Photonic integrated device for chaos applications in communications”, Phys. Rev. Lett. 100, 194101 (2008).
[2] A. Argyris, E. Grivas, M. Hamacher, A. Bogris, and D. Syvridis, “Chaos-on-a-chip secures data transmission in optical fiber links”, Opt. Express 18, 5188-5198 (2010).
[3] J. P. Toomey, C. J. McMahon, D. M. Kane, A. Argyris, and D. Syvridis, “Maps of the diverse output characteristics of a 4-section photonic integrated laser”, in 2014 International Semiconductor Laser Conference (ISLC), pp. 121-122 (2014).
[4] J. P. Toomey, D. M. Kane, C. McMahon, A. Argyris, and D. Syvridis, “Integrated semiconductor laser with optical feedback: transition from short to long cavity regime”, Opt. Express 23, 18754-18762 (2015).

 

 

Information about the data available

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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 references:

Argyris, a., Hamacher, M., Chlouverakis, K., Bogris, a., & Syvridis, D. (2008). Photonic Integrated Device for Chaos Applications in Communications. Physical Review Letters, 100(19), 194101. doi:10.1103/PhysRevLett.100.194101

Toomey, J. P., Kane, D. M., McMahon, C., Argyris, A., & Syvridis, D. (2015). Integrated semiconductor laser with optical feedback: transition from short to long cavity regime. Optics Express, 23(14), 18754. doi:10.1364/OE.23.018754

Source:

Dr Apostolos Argyris
Optical Communications Laboratory
Department of Informatics and Telecommunications
National and Kapodistrian University Of Athens
argiris@di.uoa.gr

Prof Dimitris Syvridis
Optical Communications Laboratory
Department of Informatics and Telecommunications
National and Kapodistrian University Of Athens
dsyvridi@di.uoa.gr

This data set was recorded from an experimental 4-section photonic integrated circuit (PIC) laser. The device functions as a DFB laser with optical feedback. DFB laser wavelength ~ 1561nm.

The PIC consists of a 300 µm long DFB laser section, a 200 µm variable optical attenuation section, which can either be forward biased for gain or reverse biased for attenuation, a 150 µm phase control section and a 1 cm long passive waveguide section which has a high reflective coating on the end facet to provide optical feedback.

During the experiment, 3 system parameters were varied: the optical feedback level, optical feedback phase and DFB laser injection current.

  • Optical feedback was varied by changing the bias to the gain/absorption section. Forward bias provides gain to amplify the feedback, while reverse bias attenuates the feedback.
  • Optical feedback phase was controlled by changing the current through the phase section.
  • Laser injection is controlled by directly varying the current to the DFB section of the device.

The dataset contains 342,576 files containing output power time series recorded from the laser using a fast photodiode and 12GHz realtime oscilloscope for different settings of:

  • DFB Injection (351 values = 15mA to 50mA in 0.1mA steps)
  • Feedback (101 forward bias values from 0mA to 10mA in 0.1mA steps, and 21 reverse bias values from 0V to -2V in -0.1V steps)
  • Phase (8 values from 0mA to 7mA in 1mA steps)

The filenames contain the values of each parameter at which the data was recorded. Filenames with ‘GAS’ in them correspond to forward bias applied to the gain/absorption section (amplified feedback). Filenames with ‘VAS’ in them correspond to reverse bias conditions (attenuated feedback):
e.g. IPH01.00DFB15.00GAS00.70.h5 : phase section current = 1mA, DFB section current = 15.0 mA, gain/absorption section = 0.7mA
IPH01.00DFB15.00GAS00.70.h5 : phase section current = 1mA, DFB section current = 15.0 mA, gain/absorption section = -0.7V

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 40GSamples/s (25ps per data point) and contain 80,000pts.