LFD-200 – live fiber detector

No-disconnection live fiber detection

The LFD-200 Live Fiber Detector allows you to detect traffic and measure signals anywhere on singlemode fibers without having to disconnect them. It also lets you check for signal presence before rerouting or maintenance, perform continuity tests and verify cable labeling. Based on non-destructive macrobending technology, the LFD-200 doesn’t disrupt traffic, damage or overstress the fiber, enabling efficient, accurate and reliable data acquisition.

Simple testing of multiple fiber types

EXFO’s LFD-200 is the only instrument of its kind on the market that comes with a choice of three built-in, interchangeable adapter heads, making it an all-in-one solution for live fiber detection. The handle’s storage compartment holds the extra adapter heads for simple conversion and easy testing of various fiber types.

The LFD-200 also features a unique Hold button that enables hands-free operation. Just push up the button and click it down.You are now free to operate your setup.


LFD-250B – live fiber detector

Breaking free of the limitations of traditional live fiber detectors

Traditional live fiber detectors (LFDs) use thumb-activated fiber bending at a fixed angle to enable the detector to read the power leaking from the jacket (see Figure 1). Since the bending is fixed and optimized for one wavelength and one fiber type, the bending often causes:

  • Excessive loss
  • Unreliable fiber detection (fiber activity is not detected)
  • Unreliable tone/traffic detection
  • Permanent damage to the fiber

In addition to being unreliable, the fact that they can cause excessive loss is the main reason why traditional LFDs are considered dangerous and are not used on high-data-rate routes and in long-haul-network applications.

EXFO’s LFD-250B Live Fiber Detector introduces step-motor-activated bending and makes fixed-angle bending—and the drawbacks stated above—a thing of the past.

EXFO’s LFD-250B: step-motor-activated bending, for guaranteed low loss

For all fiber types and all wavelengths, insertion loss is monitored as a function of the bending angle as the motor (and not human power) moves. Although the angles differ, the behavior remains the same. The adjacent graph shows that fixed-angle bending generates excessive loss in some cases, and leads to flawed identification in others.

The LFD-250B brings a unique approach: the power loss is monitored as the motor (and not human power) changes the angle. Therefore, the angle is automatically optimized for each fiber type and each singlemode wavelength. This results in clear-cut advantages:

  • Maximum loss of 1 dB guaranteed for any singlemode telecom fiber (most jacket types) and any wavelength
  • No damage to the fiber: bending is always minimal and the fiber is released when no power is detected*
  • Virtually 100 % reliability on traffic detection, direction identification and tone detection
  • Accurate in-line, non-disruptive power measurements
  • Safe to be used in long-haul applications and on high-payload fibers—contrary to traditional LFDs

Ambiant light offset

EXFO’s LFD-250B performs an ambient light offset prior to fiber bending, which makes it less sensitive to ambient light. A push-down cap can also be placed on the headend to block intense ambient light.

In-line power measurement

As stated, the LFD-250B controls the insertion loss within the fiber (IL) in dB. But the absolute value of the measured signal is in dBm, so knowing the loss in dB and the power level of this light exiting, power can be measured with a better accuracy than traditional fixed loss LFDs. Of course, coupling efficiency is a factor (3 mm jackets absorb more than 1.6 mm and 900 μm jackets). However, since loss is monitored as a basis for motor positioning, the unit knows what size of jacket is being tested (either 900 μm, 1.6 mm or 3 mm), so the LFD-250B automatically uses the proper coupling efficiency parameter and computes the power within any fiber, at any wavelength, with 1 dB repeatability.

Applications are numerous

  • FTTH deployment, where there is no protection fiber, making non-intrusiveness a key
  • Live network maintenance and troubleshooting
  • Link budget evaluation without having to disconnect

LFD-300B/TG-300B FiberFinder – live fiber identifier/tone generator

Pinpointing live and dark fibers: guesswork ends here

Performing network upgrade or optical testing requires a fiber to be disconnected. This is often easier said than done, since finding the right connection can be tricky, namely because of fiber mislabeling or poor record keeping. While the dark fiber can be identified using a tone generator (270 Hz, 1 kHz, 2 kHz), the live fiber identification technique often involves one technician pulling one end of the patchcord, with another technician trying to identify which patchcord is moving at the other end—a process that translates into long delays and can result in unnecessary service disruption.

Combined with the TG-300B Tone Generator, the innovative LFD-300B FiberFinder™ Live Fiber Identifier enables technicians to identify a specific live fiber without having to disconnect it and, above all, without having to guess.

This brings key benefits:

  • No more network outages as a result of fiber detection/identification procedures
  • The minimized need to access the network helps prevent errors