MHZ BROADBAND OPTICAL LINK (ISOLATED PROBE)

Our MHz Broadband Optical Link (Isolated Probe) is an optically isolated measurement solution designed to safely capture and transmit electrical signals from environments where direct electrical connections are not possible or safe.

In this system, the electrical signal is first acquired by an isolated probe transmitter, converted into an optical signal, and transmitted through a fiber optic cable to a receiver connected to standard measurement equipment such as an oscilloscope.

This architecture allows engineers to perform accurate measurements in electrically harsh environments, while ensuring complete galvanic isolation between the measurement point and the instrumentation.

For instance, these links can provide the high impedance input requested by most voltage probes, in the close vicinity of the probe and within a small volume. It will transmit the signal from an electrically noisy environment through a fibre optic cable to the 50 ohm input of the measurement device.

A differential probe measures the voltage difference between two points in a circuit. It still shares a common reference with the measurement system and may be affected by ground loops or high-voltage differences if the points are not near the system ground. Differential probes are ideal for low- to medium-voltage signals where both points are accessible and relatively safe.

An isolated probe, like Montena’s MHz broadband optical link, provides complete galvanic isolation between the measurement point and the equipment. The signal is transmitted through fiber optics, eliminating any conductive path. This allows safe measurements on floating potentials, high-voltage systems, or electrically noisy environments.

An isolated optical probe is particularly useful when measurements must be performed on floating potentials, high-voltage systems, or electrically noisy environments. Typical use cases include:

• Monitoring signals inside high-voltage systems
• Measuring control or switching signals in power electronics
• Recording fast electrical transients
• Performing measurements during EMC immunity testing

By transmitting the signal through optical fiber, the system eliminates the electrical connection between the device under test and the measurement equipment.

Montena’s isolated optical link family supports signal transmission from DC up to tens or hundreds of megahertz, depending on the model. Two main versions are available:

• MOL25T – DC to 25 MHz, high impedance input only
• MOL500T – DC to 500 MHz, high impedance or 50 ohm input

This bandwidth range is optimized for accurate measurement of electrical signals and fast transient events, rather than for RF transmission.

One of the main advantages of this system is complete galvanic isolation provided by the optical fiber. Because the signal is transmitted optically:

• There is no conductive path between the measurement point and the oscilloscope
• Ground loops are eliminated
• The operator and measurement equipment are protected from high voltages and transient events

This makes the system particularly suitable for high-voltage laboratories, power electronics testing, and EMC measurement environments.

Montena’s optical links are specifically designed for measurement applications in harsh electromagnetic environments, with:

• Compact electro-optical transmitter modules
• Battery-powered operation for flexible deployment
• High immunity to electromagnetic disturbances
• Fiber-optic transmission over long distances

These features allow measurement instruments to be placed far from the test environment, while ensuring reliable and safe signal acquisition.