scholarly journals Proposal for noise-free visible-telecom quantum frequency conversion through third-order sum and difference frequency generation

2021 ◽  
Vol 46 (2) ◽  
pp. 222
Author(s):  
Xiyuan Lu ◽  
Gregory Moille ◽  
Ashutosh Rao ◽  
Kartik Srinivasan
Keyword(s):  
Frequency Conversion ◽  
Difference Frequency Generation ◽  
Difference Frequency ◽  
Third Order ◽  
Quantum Frequency ◽  
Frequency Generation

scholarly journals Efficient idler broadening via oppositely dual-chirped difference frequency generation

2020 ◽  
Vol 8 ◽  
Author(s):  
Haizhe Zhong ◽  
Bin Hu ◽  
Saisai Hu ◽  
Shengying Dai ◽  
Ying Li ◽  
...  
Keyword(s):  
Frequency Conversion ◽  
Laser System ◽  
Difference Frequency Generation ◽  
Matching Condition ◽  
Difference Frequency ◽  
Phase Matching ◽  
Periodically Poled ◽  
Frequency Generation ◽  
Phase Matching Condition ◽  
Gain Characteristic

Dual-chirped difference frequency generation (DFG) is an advantageous technique for generating the broadband mid-infrared (IR) idler wave, which is inaccessible by a population-inversion-based laser system. In principle, the generated idler wave may even suffer a spectrum broadening compared with the driving pulsed lasers if the pump and signal waves are oppositely chirped. However, broadband phase-matching is always the determining factor for the resulting efficiency and the bandwidth of the generated idler wave. In this study, specific to an oppositely dual-chirped DFG scheme, we derive the precondition to realize broadband frequency conversion, wherein a negative $(1/\unicode[STIX]{x1D710}_{p}-1/\unicode[STIX]{x1D710}_{i})/(1/\unicode[STIX]{x1D710}_{s}-1/\unicode[STIX]{x1D710}_{i})$ , in terms of the correlation coefficient of the group velocity ( $\unicode[STIX]{x1D70E}$ ), is necessary. However, most birefringence bulk crystals can only provide the required material dispersions in limited spectral regions. We show that the periodically poled lithium niobate crystal that satisfies an inactive Type-II (eo-o) quasi-phase-matching condition has a stable negative $\unicode[STIX]{x1D70E}$ and exerts the expected broadband gain characteristic across an ultra-broad idler spectral region $(1.7{-}4.0~\unicode[STIX]{x03BC}\text{m})$ . Finally, we propose and numerically verify a promising DFG configuration to construct a tunable mid-IR spectrum broader based on the broadband phase-matched oppositely dual-chirped DFG scheme.

scholarly journals Difference-frequency generation in optically poled silicon nitride waveguides

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ezgi Sahin ◽  
Boris Zabelich ◽  
Ozan Yakar ◽  
Edgars Nitiss ◽  
Junqiu Liu ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Frequency Conversion ◽  
Difference Frequency Generation ◽  
Second Order ◽  
Difference Frequency ◽  
Parametric Oscillation ◽  
Nonlinear Frequency ◽  
Nonlinear Frequency Conversion ◽  
All Optical ◽  
Frequency Generation

Abstract Difference-frequency generation (DFG) is elemental for nonlinear parametric processes such as optical parametric oscillation and is instrumental for generating coherent light at long wavelengths, especially in the middle infrared. Second-order nonlinear frequency conversion processes like DFG require a second-order susceptibility χ (2), which is absent in centrosymmetric materials, e.g. silicon-based platforms. All-optical poling is a versatile method for inducing an effective χ (2) in centrosymmetric materials through periodic self-organization of charges. Such all-optically inscribed grating can compensate for the absence of the inherent second-order nonlinearity in integrated photonics platforms. Relying on this induced effective χ (2) in stoichiometric silicon nitride (Si3N4) waveguides, second-order nonlinear frequency conversion processes, such as second-harmonic generation, were previously demonstrated. However up to now, DFG remained out of reach. Here, we report both near- and non-degenerate DFG in all-optically poled Si3N4 waveguides. Exploiting dispersion engineering, particularly rethinking how dispersion can be leveraged to satisfy multiple processes simultaneously, we unlock nonlinear frequency conversion near 2 μm relying on all-optical poling at telecommunication wavelengths. The experimental results are in excellent agreement with theoretically predicted behaviours, validating our approach and opening the way for the design of new types of integrated sources in silicon photonics.

scholarly journals Spectroscopic Imaging with an Ultra-Broadband (1–4 THz) Compact Terahertz Difference-Frequency Generation Source

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 336
Author(s):  
Atsushi Nakanishi ◽  
Shohei Hayashi ◽  
Hiroshi Satozono ◽  
Kazuue Fujita
Keyword(s):  
Imaging Technique ◽  
Spectroscopic Imaging ◽  
Difference Frequency Generation ◽  
Difference Frequency ◽  
Quality Monitoring ◽  
Terahertz Emission ◽  
Mid Infrared ◽  
Quantum Cascade ◽  
Frequency Generation ◽  
Multi Mode

We demonstrate spectroscopic imaging using a compact ultra-broadband terahertz semiconductor source with a high-power, mid-infrared quantum cascade laser. The electrically pumped monolithic source is based on intra-cavity difference-frequency generation and can be designed to achieve an ultra-broadband multi-mode terahertz emission spectrum extending from 1–4 THz without any external optical setup. Spectroscopic imaging was performed with three frequency bands, 2.0 THz, 2.5 THz and 3.0 THz, and as a result, this imaging technique clearly identified three different tablet components (polyethylene, D-histidine and DL-histidine). This method may be highly suitable for quality monitoring of pharmaceutical materials.

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