Detector Parameters
Detection Mode
System Context
0.54
Effective QE
12.5
Shot Noise Clearance (dB)
0.089
Key Rate (bits/sym)
16
Max Symbol Rate (GBaud)
Key Rate vs Quantum Efficiency
Detector Noise Floor
Detector Technology Comparison
| Technology | QE | Bandwidth | NEP | Integration |
|---|---|---|---|---|
| InGaAs PIN | 70-85% | 10-40 GHz | ~5 pW/√Hz | Hybrid |
| Ge-on-Si | 60-80% | 20-50 GHz | ~10 pW/√Hz | Monolithic |
| Balanced (InGaAs) | 65-80% | 1-20 GHz | ~1 pW/√Hz | Hybrid |
| Integrated BPD | 50-70% | 5-25 GHz | ~15 pW/√Hz | PIC |
Balanced Detection
Advantages
- • Shot-noise limited detection
- • Common-mode noise rejection
- • LO intensity noise cancellation
- • High signal-to-noise ratio
Key Parameters
- • CMRR: 20-40 dB typical
- • Phase matching: <1° error
- • Amplitude balance: <0.5 dB
- • LO power: 1-20 mW