Optical module for imaging and spectroscopy in back focal plane
The backbone of the optical module is a cage system, which is fully modifiable, and which can be (as a whole unit) connected to a port of an optical microscope or to its trinocular. An image from the image plane of the optical microscope is then sent through relay optics (composed of two achromatic lenses in 4f configuration) to a camera chip or to a input slit of a spectrometer. One of these two output branches can be easily selected by a removable mirror. By replacing the second lens by another one with exactly half focal length, the back focal plane of the objective (Fourier plane) is imaged onto the camera or spectrometer, and angular directions of the light originating in the image plan can be studied. Easy exchange of the lenses is ensured by a system of magnetic mounts. In the exact half between the lenses there is yet another magnetic mount, which can be used to modify transfer function of the whole system by switchable apertures. Finally, removable magnetic adapter for fiber connection is placed in the first image plane in order to connect a light source or fiber spectrometer.