The eShel spectro is a professional-level multi-order fiber-optic instrument.
When you can’t choose between resolution and spectral range – as in the case of exoplanet studies, for example – then you need an Echelle spectroscope, which offers numerous orders at high resolution (R = 10,000).
The eShel spectroscope covers a spectral range of approximately 390 to 700nm (orders 32 to 53).
The complete eShel system includes the spectroscope itself, as well as the FIGU F/6 (Fiber Injection and Guiding Unit), the calibration module (with ThAr lamp), and the optical fibers (target 50µm and calibration 200µm, both 20m long).
