A single-wavelength all-optical phase modulator: towards an optical transistor

The quest for realizing an all-optical transistor while fulfilling desired criteria has been around since long time. Various schemes have been put forward over the years to achieve it; however, almost all techniques make use of at least two different laser sources. Optical event horizon principle has also been employed to see transistor action in glass fibers using two different frequency sources. In this paper, we report an optical transistor action in short-length, tailor-made multimode optical fibers through a single pump only. The higher order mode properties of the fiber and intermodal nonlinear interaction (mainly cross-phase modulation) are used to achieve efficient transistor action. Both the soliton and a weak dispersive pulse are excited in LP02and LP01modes of the fiber, respectively, with a certain temporal delay set by the sign of the differential group delay between the modes. We believe that the scheme has potential to improve system performance owing to the fact that only a single-wavelength pump source is required as opposed to the optical-transistor devices available till date that essentially require two-color pumping.The quest for realizing an all-optical transistor while fulfilling desired criteria has been around since long time. Various schemes have been put forward over the years to achieve it; however, almost all techniques make use of at least two different laser sources. Optical event horizon principle has also been employed to see transistor action in glass fibers using two different frequency sources. In this paper, we report an optical transistor action in short-length, tailor-made multimode optical fibers through a single pump only. The higher order mode properties of the fiber and intermodal nonlinear interaction (mainly cross-phase modulation) are used to achieve efficient transistor action. Both the soliton and a weak dispersive pulse are excited in LP02and LP01modes of the fiber, respectively, with a certain temporal delay set by the sign of the differential group delay between the modes. We believe that the scheme has potential to improve system performance owing to the fact that only a single-wavelength pump source is required as opposed to the optical-transistor devices available till date that essentially require two-color pumping.

Journal of Lightwave TechnologyMar 8, 20184 citations

Quantum Model for Optical Phase Modulator

A.G. Tam, Kerry James Hinton, Peter M. Farrell +1 more

Jan 1, 20090 citations

A single-molecule optical transistor

Jaesuk Hwang, M. Pototschnig, R. Lettow +4 more

NatureJul 1, 2009364 citations

Phase-Insensitive, Single Wavelength, All-Optical Transistor Based on Cascaded Second-Order Nonlinearities

Z. Wang, David J. Hagan, Sunggeon Kim +2 more

The resurgence of interest in cascaded second order nonlinearities[1,2] has resulted in several schemes for applying cascading in second-harmonic generating (SHG) crystals to optical transistor-like devices [3-7], Such devices allow a weak signal beam to impose a large amplitude modulation on a strong “pump” beam, through mixing in a χ(2) crystal. However, all of the devices reported to date require the pump and signal beams to be temporally coherent, as the process is strongly dependent on the phase between these two beams. There have been some suggestions[6,7] that type II phasematched SHG may remove phase sensitivity, but the devices proposed still require that the signal must be in phase with approximately half of the pump intensity. In this letter, we describe how one may properly exploit type II phase matching to produce a truly phase-insensitive all-optical transistor (AOT) based on second order nonlinearities.The resurgence of interest in cascaded second order nonlinearities[1,2] has resulted in several schemes for applying cascading in second-harmonic generating (SHG) crystals to optical transistor-like devices [3-7], Such devices allow a weak signal beam to impose a large amplitude modulation on a strong “pump” beam, through mixing in a χ(2) crystal. However, all of the devices reported to date require the pump and signal beams to be temporally coherent, as the process is strongly dependent on the phase between these two beams. There have been some suggestions[6,7] that type II phasematched SHG may remove phase sensitivity, but the devices proposed still require that the signal must be in phase with approximately half of the pump intensity. In this letter, we describe how one may properly exploit type II phase matching to produce a truly phase-insensitive all-optical transistor (AOT) based on second order nonlinearities.

Nonlinear OpticsJan 1, 19961 citation

Demonstration of spatial-light-modulation-based four-wave mixing in cold atoms

Jz-Yuan Juo, Jia-Kang Lin, Chin-Yao Cheng +3 more

Long-distance quantum optical communications usually require efficient wave-mixing processes to convert the wavelengths of single photons. Many quantum applications based on electromagnetically induced transparency (EIT) have been proposed and demonstrated at the single-photon level, such as quantum memories, all-optical transistors, and cross-phase modulations. However, EIT-based four-wave mixing (FWM) in a resonant double-$\mathrm{\ensuremath{\Lambda}}$ configuration has a maximum conversion efficiency (CE) of 25% because of absorptive loss due to spontaneous emission. An improved scheme using spatially modulated intensities of two control fields has been theoretically proposed to overcome this conversion limit. In this study, we first demonstrate wavelength conversion from 780 to 795 nm with a 43% CE by using this scheme at an optical density (OD) of 19 in cold $^{87}\mathrm{Rb}$ atoms. According to the theoretical model, the CE in the proposed scheme can further increase to 96% at an OD of 240 under ideal conditions, thereby attaining an identical CE to that of the previous nonresonant double-$\mathrm{\ensuremath{\Lambda}}$ scheme at half the OD. This spatial-light-modulation-based FWM scheme can achieve a near-unity CE, thus providing an easy method of implementing an efficient quantum wavelength converter for all-optical quantum information processing.Long-distance quantum optical communications usually require efficient wave-mixing processes to convert the wavelengths of single photons. Many quantum applications based on electromagnetically induced transparency (EIT) have been proposed and demonstrated at the single-photon level, such as quantum memories, all-optical transistors, and cross-phase modulations. However, EIT-based four-wave mixing (FWM) in a resonant double-$\mathrm{\ensuremath{\Lambda}}$ configuration has a maximum conversion efficiency (CE) of 25% because of absorptive loss due to spontaneous emission. An improved scheme using spatially modulated intensities of two control fields has been theoretically proposed to overcome this conversion limit. In this study, we first demonstrate wavelength conversion from 780 to 795 nm with a 43% CE by using this scheme at an optical density (OD) of 19 in cold $^{87}\mathrm{Rb}$ atoms. According to the theoretical model, the CE in the proposed scheme can further increase to 96% at an OD of 240 under ideal conditions, thereby attaining an identical CE to that of the previous nonresonant double-$\mathrm{\ensuremath{\Lambda}}$ scheme at half the OD. This spatial-light-modulation-based FWM scheme can achieve a near-unity CE, thus providing an easy method of implementing an efficient quantum wavelength converter for all-optical quantum information processing.

arXiv:1804.03306Physical Review AMay 14, 201813 citations

An atomic-scale optical modulator

R. Mark Wilson

Physics TodayFeb 25, 20160 citations

^{87}\mathrm{Rb}

atoms. According to the theoretical model, the CE in the proposed scheme can further increase to 96% at an OD of 240 under ideal conditions, thereby attaining an identical CE to that of the previous nonresonant double-$\mathrm{\ensuremath{\Lambda}}$ scheme at half the OD. This spatial-light-modulation-based FWM scheme can achieve a near-unity CE, thus providing an easy method of implementing an efficient quantum wavelength converter for all-optical quantum information processing.