Feasibility

Single photon source technologies have come a long way. The purpose of this notebook is to document - The performance benchmarks for different photon technologies - The sectors and companies that can be benefitted by those photon technologies - The projected timeline for achieving those performance benchmarks

	Sub-shot noise phase estimation	Quantum enhanced imaging	Quantum key distribution	Quantum repeaters for long-distance communication	Linear optical quantum computing	Photonic cluster state quantum computing
Requirements for true usefullness	10-photon GHZ/N00N/Holland-Burnett state

timeline
    title Single Photon Source Technology Development Eras

    section Era 1
        Basic Proof of Concept (g²(0) < 0.5)
            : Universities and research labs
            : Government research agencies
            : Defense contractors (DARPA, etc.)

    section Era 2 
        Practical QKD (g²(0) < 0.1, 10-30% efficiency, Telecom wavelengths)
            : ID Quantique
            : MagiQ Technologies
            : Toshiba Research
            : Government agencies

    section Era 3 
        Quantum Sensing (g²(0) < 0.01, >90% indistinguishability)
            : Single Quantum
            : PicoQuant
            : Hamamatsu Photonics
            : Medical imaging companies

    section Era 4 
        Quantum Computing (g²(0) < 0.001, >99% indistinguishability, >80% efficiency)
            : Xanadu
            : PsiQuantum
            : Orca Computing
            : IBM Quantum Network

    section Era 5 
        Quantum Networks (g²(0) < 0.0001, >95% efficiency)
            : Quantum Xchange
            : Toshiba Quantum Technology
            : SK Telecom
            : China Telecom

    section Era 6 
        Fault-Tolerant Systems (Room temperature, synchronized arrays, commercial applications)
            : Cloud providers (AWS, Google, IBM)
            : Semiconductor companies
            : Consumer electronics
            : Automotive industry