The EXFO IQ‑3100‑D50 is a programmable 100 dB variable optical attenuator module designed for IQS test systems, offering very low insertion loss (typ. 1.5 dB), excellent spectral uniformity (≈±0.1 dB** across WDM bands), and precise, repeatable attenuation control for EDFA and BER test applications.**

Technical Overview

The IQ‑3100 series is a family of programmable variable optical attenuator / variable reflector modules intended for automated optical test systems (IQS). The D50 variant is a 100 dB maximum attenuation module with a built‑in monitor output and high‑isolation shutter for safety and device protection. The unit supports absolute, relative and X+B attenuation modes, programmable step sequences (up to 100 steps) and long dwell times for automated scans.

Optical Performance and Key Specs

• Maximum attenuation: 100 dB.
• Typical minimum insertion loss: ~1.5 dB (wavelength dependent).
• Spectral uniformity: ±0.1 dB across the WDM band (typical 1520–1570 nm).
• Repeatability: ±0.03 dB (typical).
• High‑isolation shutter: >100 dB attenuation for safety and component protection.

Mechanical, Control and Integration

The IQ‑3100 modules are Windows‑based GUI controllable, with front‑panel keys and a documented GPIB/remote command set for scripted automation and integration into larger IQS test sequences. The instruction manual contains the full command tree, calibration procedures and maintenance guidance. The product is listed as discontinued on EXFO’s site; manuals and support resources remain available for legacy units.

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