Lasers
The Optoelectronics Section is engaged in the development of laser systems and its components for a broad range of applications. Current activities are focusing most prominently on lasers to be used in the context of global greenhouse gas monitoring, precision optical metrology, canopy mapping and altimetry. The development of laser technologies applicable to quantum systems, such as e.g. optical atomic clocks, is also an area of constantly increasing importance to us.
In the domain of atmospheric sensing laser systems for measuring the concentration of carbon dioxide, the most relevant greenhouse gas, form a key target of developments. The favoured measurement concept is based on the differential absorption of two or more emitted laser wavelengths at around 2050 nanometers. Candidate laser schemes to generate these dedicated wavelengths (with utmost accuracy and stability) comprise both direct emission from suitable solid state materials and doped fibres as well as frequency conversion of a Nd:YAG laser by optical parametric oscillation and subsequent amplification.
One of our topics in the area of precision optical metrology is the development of a laser system for a potential future mission to map the Earth’s gravity dynamical variations with unprecedented resolution. The metrology concept relies on optical interferometry between two satellites flying in a formation of up to 200 kilometres distance. For the ultra-low-noise laser system the driving requirements are utmost frequency stability and power stability. A prototype laser consisting of a non-planar ring oscillator (NPRO) frequency-locked to an ultra-stable optical cavity with subsequent low-noise amplification in an optical fibre has demonstrated the required performance and passed initial environmental tests to validate its space-worthiness.