Both HMM and HDM modes use microlenses and fibres to transmit light to the spectrographs, the principle being to make a pupil image on the fibre cores. Microlenses and fibres are directly on the tile in the focal plate for HMM, while they are offset from the focal plate, after an optical relay including a deformable mirror for HDM. In the case of HDM, the microlens surface is conjugated to the image of the sky, and acts as a high-definition sampler.
Both HMM and HDM modes use microlenses and fibres to transmit light to the spectrographs, the principle being to make a pupil image on the fibre cores. Microlenses and fibres are directly on the tile in the focal plate for HMM, while they are offset from the focal plate, after an optical relay including a deformable mirror for HDM. In the case of HDM, the microlens surface is conjugated to the image of the sky, and acts as a high-definition sampler.
