Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics & Optoelectronic Technology

All-Optical Wavelength Conversion Based on the Cascaded Sum and Difference Frequency Generation in a Periodically Poled Lithium-Niobate Waveguide

Jian Wang

Published Jan 1, 2007• 0 citations
OpenAlex

Abstract

The principle of all-optical wavelength conversion based on the cascaded sum and difference frequency generation (SFG+DFG) in quasi-phase-matched (QPM) periodically poled LiNbO3 (PPLN) waveguides is introduced. The conversion efficiency of the wavelength converter is calculated. The influences of the powers and span of two pumps on the conversion efficiency are analyzed. Bandwidth of one pump wavelength is discussed. The tuning is about 0.5 nm. The signal pulse width is compressed about 0.68 times.

Related papers

Analysis of picosecond-pulse wavelength conversion based on cascaded sum-frequency generation and difference-frequency generation in quasi-phase-matched LiNbO3 waveguides

Yong Wang, Chang-Qing Xu

Wavelength conversion based on the cascaded sum-frequency generation and difference-frequency generation (cSFG+DFG) process in quasi-phase-matched (QPM) periodically poled lithium niobate (PPLN) waveguides has the advantage of no pump occupation in the communication band, compared to the traditional cascaded second-harmonic generation (SHG) and DFG process. In cSFG+DFG-based wavelength conversion, two pump waves and a signal wave are required. The input pulse train, as a carrier of information, can be applied to either the signal or one of the two pump waves. Though the converted wave is in the form of pulses, its temporal and spectral characteristics are dependent on the arrangement of the pulsed wave. In this work, we target the wavelength conversion of 40-GHz picosecond pulse trains, and systematically analyze the temporal and spectral characteristics of the pump, signal, converted, and sum-frequency waves during their propagations in PPLN waveguides by using numerical simulation. In particular, pulse shapes, optical spectra, phases and conversion efficiency are compared when the picosecond pulse train is used as the signal and pump waves, respectively.

Optical Engineering•May 1, 2007•4 citations

Flattening of cascaded sum- and difference-frequency generation-based wavelength conversion by pump or period detuning

Shiming Gao, Changxi Yang, Xiaosheng Xiao +3 more

We investigate response flatting of cascaded sum- and difference- frequency generation (SFG/DFG)-based wavelength conversion in quasi-phase-matched (QPM) periodically poled lithium niobate waveguides for wavelength division multiplexing optical communication systems. The cascaded SFG/DFG-based configuration shows more robustly combined properties than conventional DFG-based and cascaded second-harmonic generation and DFG (SHG/DFG)-based configurations. The response fluctuation, generated while enhancing the conversion bandwidth, can be efficiently reduced by the method of pump detuning or QPM period detuning.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 24, 2005•0 citations

Comparison of cascaded χ2 wavelength conversions in quasi-phase-matched (QPM) waveguides

Bo Chen, Chang‐Qing Xu

Cascaded second-order nonlinear interaction (&chi(2));based wavelength conversion technique has attracted much attention due to its unique characteristics such as low noise and broadband, which are critical in fiber communication networks. In this report, wavelength conversions based on the newly proposed SFG-DFG (sum frequency generation - difference frequency generation) and conventional SHG-DFG (second harmonic generation - difference frequency generation) are studied and compared both experimentally and theoretically in a LiNbO3 quasi-phase matched (QPM) waveguide. It is shown that the same conversion efficiency can be achieved by employing two pump sources with only half power each (P1, P2) in the SFG-DFG scheme as compared with the SHG-DFG scheme with a single higher power pump beam (P=P1+P2). It is shown that the cascaded SFG-DFG based wavelength conversion has a larger 3-dB pump tolerance bandwidth. The theoretical results are consistent well with the experimental ones. It is found that the pump wavelength difference can be separated by a span as large as 75 nm, while 3-dB signal conversion efficiency is retained in a 45 mm-long device. It is also exhibited that tolerance of temperature for the cascaded SFG-DFG remains the same as that of the cascaded SHG-DFG based devices. The results show that the SFG-DFG wavelength conversion scheme is very attractive for practical applications.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 16, 2004•0 citations

Comparison of wavelength conversions based on cascaded second-harmonic generation/difference-frequency generation under continuous-wave and pulsed pumping

Yong Wang, Jorge Fonseca-Campos, Chang-Qing Xu +3 more

The implementation of wavelength conversion around 1.55 μm in quasi-phase-matched (QPM) periodically poled LiNbO3 (PPLN) waveguides is mostly based on the cascaded second-harmonic generation/difference-frequency generation (SHG/DFG) process. As usual, a continuous wave (CW) and a pulsed wave are injected into a PPLN waveguide. Of them, the pulsed wave is regarded as the information carrier, and the CW is taken as the control. To transfer the information of optical codes from one wavelength to another, the codes can be applied to either the signal (CW-pumped scheme) or the pump (pulse-pumped scheme). In this work, the temporal and spectral properties of wavelength conversions during pulse propagation as well as the conversion efficiency in the two pumping schemes were compared experimentally and theoretically under different conditions of input pulse width, pump power and pump central wavelength. In the experiments, we adopted an MgO-doped PPLN waveguide, and a 40-GHz tunable picosecond-pulse source. The conversion characteristics were systematically investigated when the CW and the pulsed wave were alternatively taken as the pump at the quasi-phase-matching wavelength of the device. In the theory, we solved the coupled-mode equations and explained the physical insights for the numerical results and experimental observations. The conversion properties of the two pumping schemes were quantitatively compared. The simulated results agree well with the experimental data, and the obtained results provide some guidelines for the design and application of QPM waveguides in wavelength conversion.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 11, 2006•0 citations

Ultrabroadband flattop wavelength conversion based on cascaded sum frequency generation and difference frequency generation using pump detuning in quasi-phase-matched lithium niobate waveguides

Meenu Ahlawat, Amirhossein Tehranchi, Chang Qing Xu +1 more

Flattop wavelength conversion over a 70 nm bandwidth in a 45-mm-long periodically poled lithium niobate (PPLN) waveguide based on nonlinear cascaded sum frequency generation (SFG) and difference frequency generation processes using two separated wavelengths, is realized. A 2 dB peak-to-peak ripple over the conversion bandwidth in the C band is observed when the two pumps are fixed for perfectly phase-matched SFG conversion; this is significantly reduced to 0.5 dB by slight detuning of one of the pumps to a longer wavelength. We also demonstrate multichannel broadcasting using two pumps to convert one signal wavelength to three idlers. Using the aperiodically poled lithium niobate waveguide increases the idler separation.

Applied Optics•Aug 5, 2011•11 citations

Cascaded wavelength conversions based on sum-frequency generation and difference-frequency generation

Chang‐Qing Xu, Bo Chen

A novel wavelength conversion scheme based on cascaded sum-frequency generation (SFG) and difference-frequency generation (DFG) is proposed and demonstrated in a MgO-doped LiNbO3 quasi-phase-matched waveguide. In this scheme, two pump wavelengths are set outside the communication band. It is shown that the same conversion efficiency can be achieved by use of two pump sources with lower output power (P1, P2) in this scheme compared with the conventional cascaded wavelength conversion technique based on second-harmonic generation and DFG with a single higher-power pump beam (P = P1 + P2) that is due to the use of a larger SFG nonlinear coefficient. The results significantly influence the selection of a suitable nonlinear interaction scheme for practical applications.

Optics Letters•Feb 1, 2004•51 citations
The principle of all-optical wavelength conversion based on the cascaded sum and difference frequency generation (SFG+DFG) in quasi-phase-matched (QPM) periodically poled LiNbO3 (PPLN) waveguides is introduced. The conversion efficiency of the wavelength converter is calculated. The influences of the powers and span of two pumps on the conversion efficiency are analyzed. Bandwidth of one pump wavelength is discussed. The tuning is about 0.5 nm. The signal pulse width is compressed about 0.68 times.
Wavelength conversion based on the cascaded sum-frequency generation and difference-frequency generation (cSFG+DFG) process in quasi-phase-matched (QPM) periodically poled lithium niobate (PPLN) waveguides has the advantage of no pump occupation in the communication band, compared to the traditional cascaded second-harmonic generation (SHG) and DFG process. In cSFG+DFG-based wavelength conversion, two pump waves and a signal wave are required. The input pulse train, as a carrier of information, can be applied to either the signal or one of the two pump waves. Though the converted wave is in the form of pulses, its temporal and spectral characteristics are dependent on the arrangement of the pulsed wave. In this work, we target the wavelength conversion of 40-GHz picosecond pulse trains, and systematically analyze the temporal and spectral characteristics of the pump, signal, converted, and sum-frequency waves during their propagations in PPLN waveguides by using numerical simulation. In particular, pulse shapes, optical spectra, phases and conversion efficiency are compared when the picosecond pulse train is used as the signal and pump waves, respectively.
We investigate response flatting of cascaded sum- and difference- frequency generation (SFG/DFG)-based wavelength conversion in quasi-phase-matched (QPM) periodically poled lithium niobate waveguides for wavelength division multiplexing optical communication systems. The cascaded SFG/DFG-based configuration shows more robustly combined properties than conventional DFG-based and cascaded second-harmonic generation and DFG (SHG/DFG)-based configurations. The response fluctuation, generated while enhancing the conversion bandwidth, can be efficiently reduced by the method of pump detuning or QPM period detuning.
Cascaded second-order nonlinear interaction (&chi(2));based wavelength conversion technique has attracted much attention due to its unique characteristics such as low noise and broadband, which are critical in fiber communication networks. In this report, wavelength conversions based on the newly proposed SFG-DFG (sum frequency generation - difference frequency generation) and conventional SHG-DFG (second harmonic generation - difference frequency generation) are studied and compared both experimentally and theoretically in a LiNbO3 quasi-phase matched (QPM) waveguide. It is shown that the same conversion efficiency can be achieved by employing two pump sources with only half power each (P1, P2) in the SFG-DFG scheme as compared with the SHG-DFG scheme with a single higher power pump beam (P=P1+P2). It is shown that the cascaded SFG-DFG based wavelength conversion has a larger 3-dB pump tolerance bandwidth. The theoretical results are consistent well with the experimental ones. It is found that the pump wavelength difference can be separated by a span as large as 75 nm, while 3-dB signal conversion efficiency is retained in a 45 mm-long device. It is also exhibited that tolerance of temperature for the cascaded SFG-DFG remains the same as that of the cascaded SHG-DFG based devices. The results show that the SFG-DFG wavelength conversion scheme is very attractive for practical applications.
The implementation of wavelength conversion around 1.55 μm in quasi-phase-matched (QPM) periodically poled LiNbO3 (PPLN) waveguides is mostly based on the cascaded second-harmonic generation/difference-frequency generation (SHG/DFG) process. As usual, a continuous wave (CW) and a pulsed wave are injected into a PPLN waveguide. Of them, the pulsed wave is regarded as the information carrier, and the CW is taken as the control. To transfer the information of optical codes from one wavelength to another, the codes can be applied to either the signal (CW-pumped scheme) or the pump (pulse-pumped scheme). In this work, the temporal and spectral properties of wavelength conversions during pulse propagation as well as the conversion efficiency in the two pumping schemes were compared experimentally and theoretically under different conditions of input pulse width, pump power and pump central wavelength. In the experiments, we adopted an MgO-doped PPLN waveguide, and a 40-GHz tunable picosecond-pulse source. The conversion characteristics were systematically investigated when the CW and the pulsed wave were alternatively taken as the pump at the quasi-phase-matching wavelength of the device. In the theory, we solved the coupled-mode equations and explained the physical insights for the numerical results and experimental observations. The conversion properties of the two pumping schemes were quantitatively compared. The simulated results agree well with the experimental data, and the obtained results provide some guidelines for the design and application of QPM waveguides in wavelength conversion.
Flattop wavelength conversion over a 70 nm bandwidth in a 45-mm-long periodically poled lithium niobate (PPLN) waveguide based on nonlinear cascaded sum frequency generation (SFG) and difference frequency generation processes using two separated wavelengths, is realized. A 2 dB peak-to-peak ripple over the conversion bandwidth in the C band is observed when the two pumps are fixed for perfectly phase-matched SFG conversion; this is significantly reduced to 0.5 dB by slight detuning of one of the pumps to a longer wavelength. We also demonstrate multichannel broadcasting using two pumps to convert one signal wavelength to three idlers. Using the aperiodically poled lithium niobate waveguide increases the idler separation.
A novel wavelength conversion scheme based on cascaded sum-frequency generation (SFG) and difference-frequency generation (DFG) is proposed and demonstrated in a MgO-doped LiNbO3 quasi-phase-matched waveguide. In this scheme, two pump wavelengths are set outside the communication band. It is shown that the same conversion efficiency can be achieved by use of two pump sources with lower output power (P1, P2) in this scheme compared with the conventional cascaded wavelength conversion technique based on second-harmonic generation and DFG with a single higher-power pump beam (P = P1 + P2) that is due to the use of a larger SFG nonlinear coefficient. The results significantly influence the selection of a suitable nonlinear interaction scheme for practical applications.