Flattop Efficient Cascaded χ$^{\bf {\bm (}2{\bm)}}$ (SFG + DFG)-Based Wideband Wavelength Converters Using Step-Chirped Gratings

We numerically evaluate efficient wideband wavelength converters based on quasi-phase-matched cascaded sum and difference frequency generation (SFG + DFG) using step-chirped gratings (SCG) in lossy lithium niobate waveguides, and compare them to the ones using uniform gratings, assuming a large pump wavelength difference considering a full model of depleted pump and sum-frequency waves. For the same length, appropriate critical period shifts are presented for the number of sections and chirp steps to achieve flattop conversion efficiency responses with peak-to-peak ripples less than 0.2 dB. To obtain the maximum efficiency and flat response with a decreasing chirp step of 1 nm, the criteria for the design of optimum four-section single-pass and two-section double-pass SCG-based devices, including the assignment of length (to achieve a desired bandwidth) and pump power, are presented considering a 75-nm pump wavelength difference. Also, the performances of single-pass and double-pass schemes for the two- and four-section SCG-based devices are given, respectively, and compared to those of uniform grating-based devices with and without pump detuning, assuming a 3-cm-long waveguide and 50-mW input pump powers. For the same length and power, using the SCG with fixed pumps instead of the uniform grating with detuned pumps shows a noteworthy increase in the mean efficiency to attain almost the same response flatness and bandwidth.

[1]  Wanyi Gu,et al.  A tunable wavelength conversion and wavelength add/drop scheme based on cascaded second-order nonlinearity with double-pass configuration , 2005 .

[2]  David J. Hagan,et al.  All‐optical modulation via nonlinear cascading in type II second‐harmonic generation , 1995 .

[3]  S. Yoo.  Wavelength conversion technologies for WDM network applications , 1996 .

[4]  Shiming Gao,et al.  Flat broad-band wavelength conversion based on sinusoidally chirped optical superlattices in lithium niobate , 2004 .

[5]  Gaetano Assanto,et al.  Analysis of lithium niobate all-optical wavelength shifters for the third spectral window , 1999 .

[6]  Junqiang Sun,et al.  Bandwidth and tunability enhancement of wavelength conversion by quasi-phase-matching difference frequency generation , 2003 .

[7]  Yong Wang,et al.  Polarisation-insensitive QPM wavelength converter with out-of-band pump , 2004 .

[8]  G. Stegeman,et al.  Thin film devices for all-optical switching and processing via quadratic non-linearities , 1998 .

[9]  Changyuan Yu,et al.  44-ns Continuously Tunable Dispersionless Optical Delay Element Using a PPLN Waveguide With Two-Pump Configuration, DCF, and a Dispersion Compensator , 2007, IEEE Photonics Technology Letters.

[10]  George I. Stegeman,et al.  Efficient wavelength shifting over the erbium amplifier bandwidth via cascaded second order processes in lithium niobate waveguides , 1997 .

[11]  Bo Chen,et al.  Analysis of novel cascaded /spl chi//sup (2)/ (SFG+DFG) wavelength conversions in quasi-phase-matched waveguides , 2004 .

[12]  Yanhe Li,et al.  Optimal design and applications for quasi-phase-matching three-wave mixing , 2002 .

[13]  I. Brener,et al.  1.5-μm-band wavelength conversion based on cascaded second-order nonlinearity in LiNbO3 waveguides , 1999, IEEE Photonics Technology Letters.

[15]  Guofan Jin,et al.  Chirped optical superlattices for broadband wavelength conversion , 2004, SPIE/OSA/IEEE Asia Communications and Photonics.

[16]  Toshiaki Suhara,et al.  Waveguide Nonlinear-Optic Devices , 2003 .

[17]  Antonella Bogoni,et al.  Photonic processing of 320 Gbits/s based on sum-/difference-frequency generation and pump depletion in a single PPLN waveguide. , 2009, Optics letters.

[18]  M M Fejer,et al.  1.5-microm-band wavelength conversion based on difference-frequency generation in LiNbO3 waveguides with integrated coupling structures. , 1998, Optics letters.

[19]  A. Tehranchi,et al.  Engineered gratings for flat broadening of second-harmonic phase-matching bandwidth in MgO-doped lithium niobate waveguides. , 2008, Optics express.

[20]  Francesca Parmigiani,et al.  OTDM to WDM format conversion based on quadratic cascading in a periodically poled lithium niobate waveguide. , 2010, Optics express.

[21]  G. Assanto.  Transistor action through nonlinear cascading in Type II interactions. , 1995, Optics letters.

[22]  S Trillo,et al.  All-optical processing by means of vectorial interactions in second-order cascading: novel approaches. , 1994, Optics letters.

[23]  Keisuke Shinozaki,et al.  Wavelength conversions ∼1.5 μm by difference frequency generation in periodically domain‐inverted LiNbO3 channel waveguides , 1993 .

[24]  A. Tehranchi,et al.  Improved cascaded sum and difference frequency generation-based wavelength converters in low-loss quasi-phase-matched lithium niobate waveguides. , 2009, Applied optics.

[25]  A. Tehranchi,et al.  Design of Novel Unapodized and Apodized Step-Chirped Quasi-Phase Matched Gratings for Broadband Frequency Converters Based on Second-Harmonic Generation , 2008, Journal of Lightwave Technology.

[26]  Yili Guo,et al.  Theoretical analyses and optimizations for wavelength conversion by quasi-phase-matching difference frequency generation , 2001 .

[27]  Jian Wang,et al.  Tunable Wavelength Conversion of ps-Pulses Exploiting Cascaded Sum- and Difference Frequency Generation in a PPLN-Fiber Ring Laser , 2006, IEEE Photonics Technology Letters.

[28]  A.E. Willner,et al.  All-optical signal processing using /spl chi//sup (2)/ nonlinearities in guided-wave devices , 2006, Journal of Lightwave Technology.

[29]  J. Dormand,et al.  A family of embedded Runge-Kutta formulae , 1980 .

[30]  Martin M. Fejer,et al.  1.5-μm-band wavelength conversion based on cascaded second-order nonlinearity in LiNbO 3 waveguides , 1999 .

[31]  A. Nirmalathas,et al.  Tunable All-Optical Wavelength Conversion of 160-Gb/s RZ Optical Signals by Cascaded SFG-DFG Generation in PPLN Waveguide , 2007, IEEE Photonics Technology Letters.

[32]  Alan E. Willner,et al.  All-optical digital 3-input AND gate using sum- and difference-frequency generation in a PPLN waveguide , 2005 .

[33]  Stability and bandwidth enhancement of difference frequency generation (DFG)-based wavelength conversion by pump detuning , 1999 .

[34]  Bandwidth enhancement and response flattening of cascaded sum- and difference-frequency generation-based wavelength conversion , 2006 .

[35]  A. Tehranchi,et al.  Response Flattening of Efficient Broadband Wavelength Converters Based on Cascaded Sum and Difference Frequency Generation in Periodically Poled Lithium Niobate Waveguides , 2009, IEEE Journal of Quantum Electronics.

[36]  A. Tehranchi,et al.  Wideband wavelength conversion using double-pass cascaded χ(2):χ(2) interaction in lossy waveguides , 2010 .

[37]  Yu Tian,et al.  Performance Evaluation of Tunable Channel-Selective Wavelength Shift by Cascaded Sum- and Difference-Frequency Generation in Periodically Poled Lithium Niobate Waveguides , 2007, Journal of Lightwave Technology.

[38]  Wanyi Gu,et al.  Wavelength conversions in quasi-phase matched LiNbO/sub 3/ waveguide based on double-pass cascaded /spl chi//sup (2)/ SFG+DFG interactions , 2004 .

[39]  Bong-Ahn Yu,et al.  All-optical wavelength conversion and tuning by the cascaded sum- and difference frequency generation (cSFG/DFG) in a temperature gradient controlled Ti:PPLN channel waveguide. , 2005, Optics express.

[40]  Jian Wang,et al.  Experimental demonstration of wavelength conversion between ps-pulses based on cascaded sum- and difference frequency generation (SFG+DFG) in LiNbO3 waveguides. , 2005, Optics express.

[41]  Junqiang Sun,et al.  All-Optical Format Conversions Using Periodically Poled Lithium Niobate Waveguides , 2009, IEEE Journal of Quantum Electronics.

[42]  A. Tehranchi,et al.  Novel Designs for Efficient Broadband Frequency Doublers Using Singly Pump-Resonant Waveguide and Engineered Chirped Gratings , 2009, IEEE Journal of Quantum Electronics.

[43]  M. Fejer,et al.  Cascaded /spl chi//sup (2)/ wavelength converter in LiNbO/sub 3/ waveguides with counter-propagating beams , 1999 .

[44]  A. Tehranchi,et al.  Efficient wavelength converters with flattop responses based on counterpropagating cascaded SFG and DFG in low-loss QPM LiNbO3 waveguides. , 2009, Optics express.

[45]  S. Yu,et al.  Corrections to “Wavelength Conversions in Quasi-Phase Matched LiNbO $_3$ Waveguide Based on Double-Pass Cascaded $chi^(2)$ SFG+DFG Interactions” , 2004 .