### **Keysight 86120D Multi-Wavelength Meter – Product Overview**
The **Keysight 86120D** is a high-precision **multi-wavelength meter** designed for optical communication testing, laser wavelength measurement, and spectral analysis. It offers **exceptional accuracy, fast scanning, and multi-channel capability**, making it ideal for R&D, manufacturing, and quality control in photonics and telecom applications.
**Key Features:**
1. **High-Accuracy Wavelength Measurement**
- **Wavelength Range:** 1270 nm – 1650 nm (C-band & L-band coverage)
- **Resolution:** **±0.2 ppm** (parts per million), suitable for **DWDM** systems
- **Absolute Accuracy:** Up to **±0.5 ppm** (depends on calibration)
2. **Multi-Channel Operation**
- Simultaneously measures **up to 8 wavelengths** (model-dependent)
- Ideal for **WDM (Wavelength Division Multiplexing)** and multi-laser systems
3. **Wide Dynamic Range**
- Detects low-power signals down to **-40 dBm**
- Suitable for **weak laser sources & optical amplifiers**
4. **Fast Measurement Speed**
- Rapid scanning for **real-time monitoring** and production testing
5. **Versatile Light Source Compatibility**
- Works with **DFB lasers, tunable lasers, LEDs, and broadband sources**
**Typical Applications:**
✔ **Optical Communication Testing** (DWDM, OTDR, EDFA characterization)
✔ **Laser Diode Calibration** (semiconductor & fiber lasers)
✔ **R&D and Manufacturing** (wavelength stability verification)
✔ **Spectroscopy & Photonics Research**
**Related/Upgraded Models:**
- **Keysight 86122A/B/C** (higher precision, extended wavelength range)
- **Yokogawa AQ6150 Series** (alternative high-end wavelength meter)