Table 1|.
Summary of the-state-of-the-art of monolithic photonic circuits as building blocks for a hybrid architecture. For comprehensive review covering materials platforms for monolithic quantum integrated photonics we refer the reader to [1, 36, 37]
| PLATFORM | FUNCTIONALITY | WAVEGUIDING PROPERTIES FOR SCALING | INTERFACING WITH OTHER SYSTEMS | |||||
|---|---|---|---|---|---|---|---|---|
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| Single photon generation | Solid state qubit | Electro-optic switching | Losses | Transparency window | Refractive index contrast | Operation temperature | Coupling to optical fibers | |
| Silica waveguides | Probabilistic, weak X3 |
- | - | Ultra-low | Visible-IR | weak | Room T | Matched |
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| Silicon on insulator | Probabilistic strong X3 |
- | Free-carriers, introduce losses. high speed | Moderate linear loss, high TPA nonlinear loss | for λ>1000 nm | large | Room T | Poor matching, efficient coupling realized with specially designed mode converters and grating couplers with back reflectors |
|
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| Silicon Nitride | Probabilistic strong X3 |
- | Electrostatic devices with MHz bandwidths possible | Low linear loss and TPA nonlinear loss | Visible-IR | moderate | Room T | Moderate matching, can be increased with apodized gratings, back reflectors, and mode converters |
|
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| Lithium Niobate, thin film | Probabilistic strong X2 |
- | Pockels effect, high speed | Moderate | Visible-IR | moderate | Room T | Moderate matching |
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| Aluminum Nitride | Probabilistic moderate x2 | - | Pockels effect, high speed | Moderate | UV-IR | moderate | Room T | Moderate matching |
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| GaAs | Probabilistic strong X2, on-demand QDs, high performance, possibility of electrical injection | Yes, Potential for deterministic quantum gates, single photon nonlinearitie s, memories based on spins |
Pockels effect, high speed | Moderate | for λ>900 nm | Low, enhanced in suspende d structures |
Room T for probabilistic photon pair, low temperature for on-demand QD source | Poor matching, can be improved with specially designed mode converters and grating couplers |
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| Diamond | Defects, On- demand, moderate performance | Yes, Good properties as a memory, potential for quantum gates | Electrostatic devices with MHz bandwidths possible | Large | UV-IR | moderate | Can be operated at room T, improved performance at low T | Poor matching, high efficiencies achieved with tapered fiber structures |