MPB has developed a 5W Polarization Maintaining Optical Fiber amplifier (OPA) at1064 nm for space applications. The design is a redundant system composed of 3 three stages of optical amplification with photodiodes at each stage, monitoring the output power. The saturated amplifier is to amplify a polarized, narrow linewidth input signal between 1 and 20 mW at 1064 nm to 5W output, in a temperature range from -35 ˚C to 65 ˚C. The maximum optical power is 6W in order to be able to compensate aging in the space environment due to radiation and temperature cycling, polarization, residual amplified simulated emission, and pump laser diode efficiency loss.
The goal of the project was to prepare a preliminary design the amplifier, perform the required analyses (thermal, structural, radiation, etc.), prepare the critical design of the amplifier, assess the components for use in space, build an engineering model and test the functional and environmental performance of the unit.
The main challenges that we overcame during the project were to:
- Identify off-the shelf components that suitable for use in space considering the temperature range (-35C to 65C), the vacuum and the radiation environment
- Create a design that meets the engineering budgets (volume, power consumption and mass)
- Effectively dissipate the generated heat over the full temperature range.
- Prepare assembly processes that are compatible with the space application.
- Avoid non-linear effects such as stimulated Brillouin scattering.
- High power (6W) Ytterbium amplifier
- Redundant Architecture
- Compatible with space environment:
- Radiation Tolerant
- Functionality over wide temperature range (-35C to 65C).
Here are the main features for the amplifier:
- Input power: 1 – 20 mW
- Wavelength: 1064 nm.
- Polarization maintaining (PER > 20dB).
- Redundant design.
- Output power: 6W.
- Qualification Temperature range: -35C to 65C
- Mass: < 1.6kg
- Power consumption < 33W
- Vacuum compatible
- Tested for vibration and shock
- Radiation tolerant
- Volume (246 mm x 156 mm x 65 mm)
The amplifier is based on a 3-stage architecture. Each stage contains an active fiber, laser diodes, photodiodes, and various optical components to distribute the signal and the pump power. The redundant design is based on a cold redundancy.
The preliminary design, critical design, Test readiness review for EM and test review board for EM were completed. Optimization opportunities were identified for the design and are being implemented.
The assembly process needs to be optimized for production.
COMPLETED: An EM was built and tested for functionality and environmental performance. The environmental testing showed the limit of the current unit and identified where improvement are possible. Some component specifications with potential improvements were identified.
The assembly process needs to be optimised for production.