Free Space Optical (FSO) communication has a long history, driven by the desire to send data faster and more efficiently. The highly directional nature of laser beams provides a significant security advantage over radio frequency counterparts. When combined with a secret key agreement (SKA) scheme, FSO-SKA can quickly establish a symmetric secret key that remains secure even against unbounded computational resources.

Laser-based wireless connectivity between two points is achieved through free space optical communication, which transmits signals through the atmosphere. To maintain reliable, high-quality connections even during challenging weather conditions, OFS produces various erbium and erbium-ytterbium-doped optical fibres and specialised fibre laser modules for this technology.

Recent developments in FSO communication techniques, such as optical free space wavelength division multiplexing (WDM), sub-carrier multiplexing (SCM), worldwide interoperability for microwave access (WiMAX), visible light communications (VLC), and vehicular visible light communications (VVLC), are being explored for next-generation FSO wireless terrestrial and global network architecture.

Ongoing research challenges for FSO systems include applications in the Internet of Things/Everything (IoT/IoE), 5G communication, mobile networks, teraherts spectrum, quantum communication, and underwater optical applications. Numerous challenges must be addressed in future research to realise the full potential of FSO communication systems.

Free Space Communications TowerFree Space Communications Tower

A Brief History of Free Space Optical Communications

Before we dive into the new fibre solutions developed by OFS, Lightera, and Furukawa Electric, let's take a quick look at the journey FSO technology has taken to become what it is today.

Early Beginnings: Light-based communication dates back to ancient times. People used signal fires and heliographs to send messages over long distances. However, these methods were basic and only worked well in clear weather.

The Laser Revolution (1960s): The invention of the laser in the 1960s changed everything. Lasers provided a focused, consistent light source that could transmit data farther than ever before. This breakthrough laid the groundwork for today's FSO technology.

Military and Space Uses (1970s–1980s): FSO gained traction for secure military communications and satellite links during the Cold War, as regular radio waves were easily intercepted. NASA also explored laser-based communication systems for distant space missions.

Business Success and Tech Growth (1990s–2000s): Advancements in laser diodes, optical amplifiers, and photodetectors allowed FSO to expand into business applications. Cities began using FSO to back up fibre networks, connect last-mile areas, and recover from disasters due to its quick setup.

Modern Era (2010s–Present): Today, FSO plays a crucial role in 5G networks, ground-to-satellite links, and data centers that manage vast amounts of information. It can deliver speeds of billions of bits per second without the need for physical wires, making it an excellent choice for dynamic, data-hungry applications.

OFS and Furukawa Electric Collaborations in FSO Communications

OFS and Lightera are leading innovators in the fibre optics industry. OFS R&D collaborates with clients and the industry to develop solutions that transform optical communications and photonics globally. OFS PRC drives the development and manufacturing of these solutions for market release.

OFS Labs merges the legacy of Bell Labs (7 Nobel Prizes, 12 Laureates) with Furukawa research expertise, forming a premier center for optical innovations. Together, OFS and Furukawa Electric have advanced FSO communication technology significantly.

Very Large Mode Area (VLMA) Erbium-Doped Fibre Amplifier Module

Key Technical Features:

  • Core Diameter: 50 μm to produce diffraction-limited output optimised to amplify high-power signals.
  • Amplification Performance: Helps amplify high bit-rate data to powers over 50 W and 1 ns pulses up to 100 μJ with peak powers reaching 100 kW.
  • Design Flexibility: Comes in both polarisation-maintaining (PM) and non-PM versions.

Applications:

  • Free space communications
  • LIDAR systems
  • Femtosecond chirped pulse amplification (CPA)

The large mode area reduces nonlinear effects to a minimum ensuring stable performance even in high-energy environments—an essential requirement for modern FSO networks.

Very Large Mode Area Erbium-Doped Fiber Amplifier Module – Data Sheet (PDF)

Very Large Mode Area (VLMA) Erbium Doped Fiber Amplifier ModuleVery Large Mode Area (VLMA) Erbium Doped Fiber Amplifier Module
Amplifier example graphs for VLMAAmplifier example graphs for VLMA

Raman Fibre Laser Module

Technical Highlights:

  • Wavelength Range: 1150–1850 nm with output power up to 150 W at 1480 nm.
  • Pump Efficiency: Optimised to enhance the output power and efficiency of Erbium-Doped Fibre Amplifiers (EDFAs).
  • Thermal Management: New design cuts down thermal load allowing for non-stop high-power operation.

Use Cases:

  • High-brightness fibre laser pumping
  • Solid-state laser applications
  • Medical technologies and precision measurement

This module's in-band core pumping technique has an influence on energy transfer, cuts down the quantum defect, and allows for scalable power outputs—a key feature to implement high-capacity optical networks.

Raman Fiber Laser Module – Data Sheet

Raman Fiber Laser ModuleRaman Fiber Laser Module
Power performance over time with output examplePower performance over time with output example

Erbium-Ytterbium Optical Fibre

Core Features:

  • Dual Doping: Boosts amplification efficiency while keeping signal integrity over long distances.
  • High-Power Handling: Strong design ensures it works in tough environmental conditions.
  • Broad Compatibility: Meets modern high-speed data needs for ground-to-satellite and terrestrial communication links.

By combining the helpful qualities of erbium and ytterbium, this optical fibre produces better brightness and operates with less noise making it essential for modern FSO uses.

Erbium-Ytterbium Optical Fibers – Brochure

Erbium-Ytterbium Optical FiberErbium-Ytterbium Optical Fiber

 

 

The Road Ahead

The progress of FSO communication from old signaling methods to today's laser-based networks shows how people keep pushing for better technology. AusOptic is proud to work with OFS, Lightera and Furukawa Electric as they develop new solutions that meet current needs and prepare for tomorrow's connection challenges.

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