Narrow-Pulse DAS Module With 3-Metre Spatial Resolution

Product Introduction

This DAS Integrated Module is specially engineered for short-range, high-precision monitoring applications with a leading 3-meter high spatial resolution—achieved at a 10km monitoring distance with an ultra-narrow 20ns pulse width output. Operating at a stable 80MHz center frequency, it only requires a single 250MHz sampling rate data acquisition card for seamless operation, simplifying system integration. For long-distance monitoring up to 40km (≤40km), it supports a 10-meter spatial resolution, balancing high precision and flexible sensing distance for diverse fiber optic vibration monitoring needs.

Current latest version: V2.02

Core Features

• 3m High Spatial Resolution : 3m ultra-high precision at 10km monitoring distance (20ns pulse width), ideal for short-range high-accuracy sensing
• Ultra-narrow Pulse Width : 20ns-500ns adjustable pulse width, supports high-resolution and flexible distance monitoring
• Dual Channel Option : 1/2 channels available, meets single/multi-path fiber optic sensing application requirements
• Simplified Integration : Matches 250MHz sampling rate acquisition card, 80MHz center frequency, plug-and-play for quick deployment
• Flexible Monitoring Distance : Supports up to ≤40km sensing, 10m spatial resolution for 30km+ long-distance scenarios
• Standard Interfaces : SMA female output/input, FC/APC fiber optic connectors, Modbus communication protocol for easy parameter adjustment

Internal optical path structure

The narrow-pulse DAS module is the black solid-line rectangle shown in the figure above. The algorithm implementation section below is implemented in the FPGA of the acquisition card.
For information on selecting a capture card, please see here.

Parameters

Mechanical Dimension Drawing

The following dimensions apply to the ultra-narrow pulse integrated DAS/DVS module and its acoustic-optical modulator driver. The overall module dimensions are 163 × 134 × 42 mm (excluding connectors and fiber). To ensure adequate thermal dissipation, install the module in an environment with sufficient ventilation. When not in use, cover the fiber flange and coaxial connectors with their respective protective caps to prevent contamination.

Interface Definition

The interface definition for the ultra-narrow pulse integrated DAS/DVS module is as follows:

Ordering Information

Unboxing Inspection

Open the product packaging box and refer to the table below to confirm that the following accessories are included. If any items are missing, please contact us promptly.

Hardware Debugging

Before beginning installation, be sure to carefully read the *User Manual* and follow the operating procedures specified therein for installation and commissioning.

The test setup is shown in the figure below. Since the Sensor port emits a high optical power (approximately 220 mW), ensure that the Sensor port is connected to a sensing fiber or a flange for attenuation before powering on the device. Do not look directly into this port.

Connect the entire module to the sensing system and use the serial port to adjust the  amplifier power, VOA value, and other parameters.

For use with a DAS acquisition card

Selecting an Acquisition Card: Depending on the intermediate frequency (IF) you choose, if it is 80 MHz, you can select an acquisition card with a 250 MHz sampling rate; if it is 200 MHz, choose an acquisition card with a 1 GHz sampling rate.