Andrey B. Krysa

Publications (90) View all

• Source

  Available from: Andrey B. Krysa

  Conference Proceeding: Near-field imaging of the evanescent electric field on the surface of a quantum cascade laser

  V. Moreau, P.-A. Lemoine, M. Bahriz, Y. De Wilde, R. Colombelli, R. Perahia, O. Painter, L. Wilson, A. Krysa
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  ABSTRACT: This paper demonstrates quantum cascade (QC) lasers employing waveguides based on air-confinement can be implemented on structures where the active region is located immediately at the device top surface, while previous devices featuring this architecture made use of thick top, doped semiconductor claddings to provide uniform current injection. The second part of the paper presents the imaging of the evanescent electric field at the device top surface performed with a mid-IR apertureless scanning near-field optical microscope (SNOM).
  Lasers and Electro-Optics, 2007 and the International Quantum Electronics Conference. CLEOE-IQEC 2007. European Conference on; 07/2007
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  Available from: Andrey B. Krysa

  Article: Design, fabrication and characterisation of InGaAs/InP single-photon avalanche diode detectors

  Ryan E Warburton, Sara Pellegrini, Lionel Tan, Jo Shien Ng, Andrey Krysa, Kris Groom, John P. R. David, Sergio Cova, Gerald S. Buller
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  ABSTRACT: This paper demonstrates the performance of planar geometry InGaAs/InP avalanche diodes, specifically designed and fabricated for Geiger-mode operation at wavelengths around 1550nm, in terms of dark count rate, single-photon detection efficiency, afterpulsing and photon-timing jitter.
  06/2006;
• Source

  Available from: Russell Gwilliam

  Article: Signal stability in periodically amplified fiber transmission systems using multiple quantum well saturable absorbers for regeneration

  E. Burr, M. Pantouvaki, M. Fice, R. Gwilliam, A. Krysa, J. Roberts, A. Seeds
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  ABSTRACT: The use of multiple quantum well (MQW) saturable absorbers (SAs) for signal regeneration in periodically amplified fiber transmission systems is explored. A systematic study of signal destabilization resulting from incomplete saturation of MQW SAs used for regeneration, and of means of overcoming such destabilization, is presented. A computer model for MQW SAs, which considers the asymmetric Fabry-Pe´rot (AFP) cavity structure commonly employed to increase the contrast of such devices, is presented. The model is used to simulate nitrogen-implanted MQW SAs with < 5 ps recovery time in a transmission system. A comparison is made with results previously obtained for a 10 Gb/s standard single-mode fiber (SMF) recirculating loop transmission experiment using MQW SAs and temporary soliton propagation for signal regeneration. The simulations allow the benefits derived from the two parts of the regenerator to be identified, as well as their contributions to the destabilization of the propagating signal. The error-free transmission distance is improved from ∼ 2000 to > 7000 km when the two components are combined.
  Journal of Lightwave Technology 03/2006; 24(2):747- 754. · 2.78 Impact Factor
• Article: Fabrication of novel quantum cascade lasers using focused ion beam (FIB) processing

  I M Ross, W H Ng, L R Wilson, I J Luxmoore, J W Cockburn, A Krysa, A G Cullis, J S Roberts
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  ABSTRACT: Focussed ion beam (FIB) processing has been applied to the fabrication of novel InP-based cleaved coupled cavity (CCC) quantum cascade lasers (QCL). Gas assisted etching using XeF2 has been shown to significantly reduce the redeposition of sputtered material onto the mirror surfaces during final milling. For the unprocessed laser a broad spread of lasing peaks are observed between 9.72µm to 9.78µm at a current of 380mA (1kA/cm−2). After FIB processing, substantial side mode suppression is observed on applying a current of 20mA (100A/cm−2) to the short section and the main lasing peak is observed at 9.77µm.
  Journal of Physics Conference Series 02/2006; 26(1):215.
• Article: High speed InAs electron avalanche photodiodes overcome the conventional gain-bandwidth product limit.

  Andrew R J Marshall, Pin Jern Ker, Andrey Krysa, John P R David, Chee Hing Tan
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  ABSTRACT: High bandwidth, uncooled, Indium Arsenide (InAs) electron avalanche photodiodes (e-APDs) with unique and highly desirable characteristics are reported. The e-APDs exhibit a 3dB bandwidth of 3.5 GHz which, unlike that of conventional APDs, is shown not to reduce with increasing avalanche gain. Hence these InAs e-APDs demonstrate a characteristic of theoretically ideal electron only APDs, the absence of a gain-bandwidth product limit. This is important because gain-bandwidth products restrict the maximum exploitable gain in all conventional high bandwidth APDs. Non-limiting gain-bandwidth products up to 580 GHz have been measured on these first high bandwidth e-APDs.
  Optics Express 11/2011; 19(23):23341-9. · 3.59 Impact Factor