// QORCH · T4.2 Photon Transfer · Working Tool
Link-Budget Calculator
Estimate end-to-end heralding efficiency, entanglement rate, and cost-per-logical-op for a photonic quantum link between two vendor platforms. This is the QORCH T4.2 engineering model running in your browser — no signup, no API key.
Link parameters
Wavelength mismatch 770 nm between native platforms adds a QFC conversion penalty automatically.
IonQ → IBM
Heralded fidelity
0.000%
Entanglement rate
2.5 Hz
Heralding eff.
0.4970%
Total link loss
22.3 dB
Round-trip latency
1.83 ms
QEC overhead
66×
Cost per logical op
$0.0693
at 66× physical link-entanglements per logical op
Bottleneck
Wavelength conversion dominates — pick matching native wavelengths
Cross-vendor comparison at 50 km
| Pair | Fidelity | Rate | Loss | $/logical |
|---|---|---|---|---|
| IonQ → IBM | 0.00% | 2.5 Hz | 22 dB | $0.0693 |
| IonQ → Google | 0.00% | 2.5 Hz | 22 dB | $0.0792 |
| Quantinuum → IBM | 0.00% | 2.5 Hz | 22 dB | $0.1122 |
| QuEra → Google | 0.00% | 2.5 Hz | 22 dB | $0.0858 |
Model assumptions. Free-space uses 0.25 dB/km clear-air attenuation and geometric spreading; fibre uses 0.2 dB/km at 1550 nm; satellite assumes a 160 dB GEO budget with 250 ms processing. Wavelength mismatch adds a Sagnac-PPLN QFC penalty. Heralded fidelity is bounded by dark-count ratio, source intrinsic fidelity, and an approximate multi-pair term. These are engineering estimates for planning, not guarantees — a real deployment needs measured device parameters.