Multi-Cavity Photon Sources for Spectrally Separated Pairs
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Solution Overview
Problem
Conventional single-photon sources have limited efficiency and reliability in generating single photons, often producing multiple photons or none at all, and fail to separate photon pairs effectively from the input beam.
Innovation Solution
A photon source device with multiple resonant cavities and reflectors is used to generate and separate photon pairs, employing a substrate with waveguides and reflectors to output distinct wavelengths, enhancing spectral separability and reducing losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single resonant cavity is used to generate photon pairs, then the device structure is simple, but the spectral separability of photon pairs from the input beam is poor and photon loss increases
Solution Approach 1:
The patent divides the single resonant cavity into two separate resonant cavities: a pump cavity for the input beam and a signal/idler cavity for the generated photon pairs. This segmentation allows independent optimization of each cavity for its specific function, improving spectral separability and reducing photon loss while maintaining manageable structural complexity
Solution Approach 2:
The patent extracts the signal and idler photons from the pump beam by using a second resonant cavity that is distinct from the pump cavity. This extraction mechanism enables effective separation of photon pairs from the input beam, reducing spectral overlap and photon loss
2Productivity
If the input beam propagates with signal and idler photons in the same direction, then momentum conservation is satisfied, but separating the photon pairs from the input beam reduces the yield and efficiency
Solution Approach 1:
The patent segments the optical paths by using two separate resonant cavities with different orientations. The pump cavity and signal/idler cavity are arranged such that they can be spatially separated, allowing efficient extraction of photon pairs without reducing yield
Solution Approach 2:
The patent introduces spatial dimensionality by orienting the second resonant cavity at an angle relative to the first pump cavity. This angular arrangement enables spectral and spatial separation of photon pairs from the input beam while maintaining momentum conservation, thereby improving efficiency and reducing photon loss
3Reliability
If conventional single-photon sources are used, then the device is simple, but the efficiency and reliability of single-photon generation is limited
Solution Approach 1:
The patent segments the photon generation process into distinct functional components: a pump cavity for input beam processing and a separate signal/idler cavity for photon pair generation. This segmentation improves reliability by allowing independent optimization of each component while keeping the overall structure manageable
Solution Approach 2:
The patent introduces waveguides and reflectors as intermediary elements to couple the two resonant cavities and direct the photon paths. These intermediaries enable efficient energy transfer and spatial separation, improving single-photon generation reliability without excessive complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves higher efficiency and reliability in generating single photons with improved spectral separability, reducing photon losses and increasing the success rate of single-photon generation.
Implementation Method 1
Spontaneous four-wave mixing is a phenomenon that may be used for generating photon pairs (e.g., a signal photon and an idler photon) from an input beam (e.g., coherent light, such as a laser beam)
Implementation Method 2
The first waveguide extends along a first axis, and is coupled with a first pair of reflectors defining a first resonant cavity in the first waveguide
Data Source
AI summary
A method includes receiving input light having an input wavelength in a first optical resonator for causing resonance of the input light in the first optical resonator. The first optical resonator includes a non-linear optical medium. The method also includes converting at least a portion of the input light to a combination of first output light having a first output wavelength that is different from the input wavelength and second output light having a second output wavelength that is different from the input wavelength and the first output wavelength by passing the input light through the non-linear optical medium. The method further includes causing resonance of the first output light and the second output light in a second optical resonator. A portion of the first optical resonator is coupled to a portion of the second optical resonator.