MERLIN, a Franco-German satellite, is ready for a 2025 launch into the space to determine the amount of methane deposited in the Earth’s atmosphere. Ferdinand-Braun-Institut in Berlin provided for the LiDAR measurement structure. As we speak now, it has also conveyed all the required laser diode benches to the partner of the plan.
The main operation that MERLIN will carry out is to determine the impacts posed by methane-a green gas to global warming. The satellite has a structure that resembles a radar laser system, and it measures natural and the origin of methane emissions. The Integrated Path Differential Absorption (IPDA)-LiDAR works by conveying laser to the surface of the Earth and then examines the released signal.
The Ferdinand-Braun-Institute (FBI) is done with the process of making the ultimate reliable laser diode benches (LDB) that MERLIN satellite will use during its mission. Six of the LDBs qualified for space operations have now been assimilated into three pump systems from the Fraunhofer Institute for Laser Technology (ILT). They will be conveyed later to the project partner in carrying out specified functions. Those structures produce the required pump energy to be used by an electronic circuit of an Nd: YAG, a solid-state laser. Later on, the ILT will assimilate it into the LiDAR structure. In turn, the solid-state laser starts to act as the source of light for a tunable Optical Parametric Oscillator (OPO), which will then produce a couple of pulses composed of varied wavelengths. Methane strongly absorbs one of the wavelengths, while the other one is not. This process, methane’s content, can be ascertained by reading the ratios of intensities present on the backscattered light.
Each of LDB produces a pump power of 60 watts in a couple of pulses, and it has a recurring rate of 20 hertz and a wavelength of the 150-microsecond pulse. To ensure that enough light is produced, laser diode minibars must be present in the LDB structure.
The latest technology has incorporated swift axis focusing lenses fitted in the LDB, enabling the laser beams to be coupled onto an optical fibre. A couple of LBDs have installed into each system and the provision of a combined power pump of 120 Watts. FBH carried out comprehensive experiments on technologies used on fast axis lens focus, laser diode and LDB, which it later recommended to be used in space operations.
Later on, the European Space Research and Technology Center (ESTEC) approved the use of diode benches. According to ESTEC’s findings, the power lowers slowly after operating for a long time of four billion pulses.