Frequency up-conversion is an effective method of mid-infrared(MIR) detection by converting long-wavelength photons to the visible domain, where efficient detectors are readily available. Here, we generate MIR light c...Frequency up-conversion is an effective method of mid-infrared(MIR) detection by converting long-wavelength photons to the visible domain, where efficient detectors are readily available. Here, we generate MIR light carrying orbital angular momentum(OAM) from a difference frequency generation process and perform up-conversion on it via sum frequency conversion in a bulk quasi-phase-matching crystal. The maximum quantum conversion efficiencies from MIR to visible are 34.0%, 10.4%, and 3.5% for light with topological charges of 0, 1, and 2, respectively, achieved by utilizing an optimized strong pump light. We also verify the OAM conservation with a specially designed interferometer, and the results agree well with the numerical simulations. Our study opens up the possibilities for generating, manipulating, and detecting MIR light that carries OAM, and will have great potential for optical communications and remote sensing in the MIR regime.展开更多
The change in the relative phase between two light fields serves as a basic principle for the measurement of the physical quantity that guides this change.It would therefore be highly advantageous if the relative phas...The change in the relative phase between two light fields serves as a basic principle for the measurement of the physical quantity that guides this change.It would therefore be highly advantageous if the relative phase could be amplified to enhance the measurement resolution.One well-known method for phase amplification involves the use of the multi-photon number and path-entangled state known as the NOON state;however,a high-number NOON state is very diffcult to prepare and is highly sensitive to optical losses.Here we propose and experimentally demonstrate in principle a phase amplifer scheme with the assistance of a harmonic generation process.The relative phase difference between two polarization modes in a polarized interferometer is amplified coherently four times with cascaded second-harmonic generation processes.We demonstrate that these amplification processes can be recycled and therefore have the potential to realize much higher numbers of multiple amplification steps.The phase amplification method presented here shows considerable advantages over the method based on NOON states and willbe highly promising for use in precision optical measurements.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 92065101 and 11934013)Anhui Initiative In Quantum Information Technologies (Grant No. AHY020200)。
文摘Frequency up-conversion is an effective method of mid-infrared(MIR) detection by converting long-wavelength photons to the visible domain, where efficient detectors are readily available. Here, we generate MIR light carrying orbital angular momentum(OAM) from a difference frequency generation process and perform up-conversion on it via sum frequency conversion in a bulk quasi-phase-matching crystal. The maximum quantum conversion efficiencies from MIR to visible are 34.0%, 10.4%, and 3.5% for light with topological charges of 0, 1, and 2, respectively, achieved by utilizing an optimized strong pump light. We also verify the OAM conservation with a specially designed interferometer, and the results agree well with the numerical simulations. Our study opens up the possibilities for generating, manipulating, and detecting MIR light that carries OAM, and will have great potential for optical communications and remote sensing in the MIR regime.
基金the National Natural Science Foundation of China(NSFC)(11934013,92065101)Anhui Initiative in Quantum Information Technologies(AHY020200)Innovation Program for Quantum Science and Technology(2021ZD0301100).
文摘The change in the relative phase between two light fields serves as a basic principle for the measurement of the physical quantity that guides this change.It would therefore be highly advantageous if the relative phase could be amplified to enhance the measurement resolution.One well-known method for phase amplification involves the use of the multi-photon number and path-entangled state known as the NOON state;however,a high-number NOON state is very diffcult to prepare and is highly sensitive to optical losses.Here we propose and experimentally demonstrate in principle a phase amplifer scheme with the assistance of a harmonic generation process.The relative phase difference between two polarization modes in a polarized interferometer is amplified coherently four times with cascaded second-harmonic generation processes.We demonstrate that these amplification processes can be recycled and therefore have the potential to realize much higher numbers of multiple amplification steps.The phase amplification method presented here shows considerable advantages over the method based on NOON states and willbe highly promising for use in precision optical measurements.
