Andersen, Lasse Mejling

Christensen, Jesper

Rottwitt, Karsten

Four-wave mixing does according to various models allow for arbitrary pulse-reshaping of the generated idler. Using subpicosecond pulses, we investigate numerically whether nonlinear effects and dispersion broadening begin to prevent this ability

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 20, 2017Nonlinear Pulse-reshaping of Sub-picosecond Pulses by Non-degenerate Four-waveMixingChristensen, Jesper; Andersen, Lasse Mejling; Rottwitt, KarstenPublication date:2013Document VersionPublisher's PDF, also known as Version of recordLink back to DTU OrbitCitation (APA):Christensen, J., Andersen, L. M., & Rottwitt, K. (2013). Nonlinear Pulse-reshaping of Sub-picosecond Pulses byNon-degenerate Four-wave Mixing. Abstract from Australia and New Zealand Conference on Optics andPhotonics (ANZCOP 2013), Perth, Australia.Australian & New Zealand Conference on Optics & Photonics. 8 – 11 December 2013 Technical Session 1- Quantum Information Theory. Wednesday 11 December 1115 - 1230   Nonlinear Pulse-reshaping of Sub-picosecond Pulses by Non-degenerate Four-wave Mixing Jesper Christensen1, Lasse Mejling1, and Karsten Rottwitt1 1Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark s103108@student.dtu.dk    Four-wave mixing does according to various models allow for arbitrary pulse-reshaping of the generated idler. Using sub-picosecond pulses, we investigate numerically whether nonlinear effects and dispersion broadening begin to prevent this ability. Keywords; Nonlinear Optics, Four-wave Mixing, Quantum Information Processing. VII.  INTRODUCTION Quantum information networks depend on the ability to propagate quantum states between linked quantum nodes in a way such that the initial quantum state is preserved [1]. To optimize the information processing an effective process capable of reshaping and frequency converting (FC) quantum states is needed. One way to obtain quantum-state-preserving FC is using non-degenerate four-wave mixing (FWM) in the specific form called Bragg Scattering (BS) [2,3]. In BS, pumps p and q, enable energy conversion from a signal to an idler wave through a nonlinear interaction between the four fields. Analytical models, predict the ability of arbitrary pulse-reshaping if pump p co-propagates with the signal and pump q co-propagates with the idler [4]. A key parameter of the conversion process is the conversion strength parameter   ||/2 ,1,12/1 srqpK EE EEJJ  , which contain the Kerr coefficient KJ , the pump energies),( qpE , and the inverse group speeds of the signal and idler ),(,1 srE . In this work we investigate whether the reshaping ability is altered when pulses in the sub-picosecond regime are considered. VIII. NUMERICAL RESULTS To investigate the pulse-shape, we solve the GNLSE using the split-step Fourier method, setting 25.0 J , and using a fiber length ||/1010 ,1,10 srwo TLL EE   . It is assumed that the natural output modes are Hermite-Gaussian such that the idler-amplitude can be expanded in a basis of these. In Figure 1, the separability ܵ defined as the ratio between the zeroth order expansion coefficient and the sum of all the coefficients is plotted vs. the pulse width ଴ܶ which in this case is the same for all pulses. In another approach, using the selectivity ܵǯ defined as the product between S and the lowest-order conversion efficiency, only the width of pump q is varied, which gives different results shown in Figure 2. This result only includes the solution of the full GNLSE in the case of down conversion. The most striking result is the indication that a given pulse-width has a corresponding fiber length yielding maximal selectivty.   Figure 1. The separability vs. pulse width of the three initial pulse amplitudes.   Figure 2. The selectivity vs. pulse width of pump q for four lengths. The initial widths of pump p and the signal is 10 ps. IX. CONCLUSION Pulse-reshaping is prevented in the sub-picosecond regime as a result of dispersion and nonlinear phase modulation. Especially, in the case where the pump-widths differ, reshaping becomes difficult as the fiber length is effectively proportinal to the width of the broadest pump.  REFERENCES 1. Tanzilli et al., Nature (London) 437, 116-120 (2005). 2. A. S. Clark, S. Shahnia, M. J. Collins, C. Xiong, and B. J. Eggleton, Opt. Lett. 38, 947-949 (2013). 3. C. J. McKinstrie, J. D. Harvey, S. Radic, M. G. Raymer, Opt. Express, 13, 9131 (2005).   C. J. McKinstrie, L. Mejling, M. G. Raymer, K. Rottwitt, Phys. Rev. A 85, 053829 (2012).  

Nonlinear Pulse-reshaping of Sub-picosecond Pulses by Non-degenerate Four-wave Mixing

http://orbit.dtu.dk/ws/files/75289898/jesperPr%C3%A6s.pdf

Nonlinear Pulse-reshaping of Sub-picosecond Pulses by Non-degenerate Four-wave Mixing

Abstract

Similar works

Full text

Available Versions

Online Research Database In Technology