Agilent/Keysight 83485A Lightwave Clock Recovery Module

The Agilent/Keysight 83485A Lightwave Clock Recovery Module is a high-performance optical receiver for precise testing and characterization of high-speed optical communication systems. It recovers clocks from optical signals with closed eyes—essential when direct clock triggers are unavailable or unsuitable for compliance testing. The module operates across 1000 nm to 1600 nm with calibrated wavelengths at 1310 nm and 1550 nm, supporting data rates from OC-3/STM-1 (155 Mb/s) through OC-192/STM-64 (9953 Mb/s). Available in 12.4 GHz and 20 GHz bandwidth configurations, it delivers –10 dBm sensitivity and transition times under 25 ps on the optical channel. The electrical output provides adjustable loop bandwidth and selectable peaking for optimal measurement accuracy. RMS noise reaches 8–15 μW on the optical side and 0.25–0.5 mV electrically, depending on bandwidth selection. Maximum input power handling is 2 mW average and 10 mW peak, non-destructive. Scale factors range from 20–500 μW/division optically and 1–100 mV/division electrically, with ±500 mV programmable dc offset on the electrical channel. CW accuracy specifications include ±25 μW ±2–4% error bands, and dc accuracy reaches ±0.4% of full scale ±2 mV ±1.5–3% of offset-corrected readings. Operating temperature is +10°C to +40°C, with full warranted performance after 1 hour stabilization. The module integrates with Keysight’s 86100 Infiniium series and accepts user-selectable fiber input connectors (e.g., Diamond HMS-10/HP universal) with 33 dB input return loss.

– Technical Specifications

Optical Channel
• Bandwidth: 12.4 GHz / 20 GHz (unfiltered)
• Wavelength range: 1000 nm to 1600 nm
• Calibrated wavelengths: 1310 nm / 1550 nm
• Supported data rates: OC-3/STM-1 (155 Mb/s), OC-12/STM-4 (622 Mb/s), OC-48/STM-16 (2488 Mb/s), OC-192/STM-64 (9953 Mb/s)
• Sensitivity: –10 dBm
• Transition time: < 25 ps
• RMS noise (characteristic): 8 μW (12.4 GHz), 15 μW (20 GHz)
• RMS noise (maximum): 12 μW (12.4 GHz), 25 μW (20 GHz)
• Scale factor: 20–500 μW/division
• CW accuracy: ±25 μW ±2% (12.4 GHz), ±25 μW ±4% (20 GHz)
• Input return loss: 33 dB

Electrical Channel
• Bandwidth: 12.4 GHz / 20 GHz
• Transition time: 28.2 ps (12.4 GHz), 17.5 ps (20 GHz)
• RMS noise (characteristic): 0.25 mV (12.4 GHz), 0.5 mV (20 GHz)
• RMS noise (maximum): 0.5 mV (12.4 GHz), 1 mV (20 GHz)
• Scale factor: 1–100 mV/division
• DC accuracy: ±0.4% of full scale ±2 mV ±1.5% (12.4 GHz), ±3% (20 GHz)
• Programmable dc offset: ±500 mV

General
• Maximum input power: 2 mW average, 10 mW peak (non-destructive)
• Operating temperature: +10°C to +40°C
• Stabilization time: 1 hour continuous operation

– Key Features

• Clock recovery from low-quality optical signals with closed eyes
• Dual-bandwidth options (12.4 GHz / 20 GHz) for varied measurement demands
• Adjustable loop bandwidth and selectable peaking for signal conditioning
• Low RMS noise: 8–15 μW optically, 0.25–0.5 mV electrically
• Broad wavelength coverage (1000–1600 nm) with calibrated C and L band support
• User-selectable fiber input connectors with high return loss rejection (33 dB)
• Programmable electrical offset (±500 mV) for flexible test setups

– Typical Applications

• Transmitter and receiver characterization in OC-3 through OC-192 systems
• Compliance testing where direct clock extraction is impractical
• Eye diagram acquisition and jitter analysis on degraded optical channels
• Multi-rate optical signal analysis across extended wavelength ranges

– Compatibility & Integration

Integrates with Keysight 86100 Infiniium digital communication analyzers. Accepts Diamond HMS-10/HP universal and equivalent user-selectable fiber connectors.