Figure1: UV sources.
The image on the left illustrates the construction of two UV
light sources to be added to the microscope for fluorescence imaging and
The left source is a 405 nm laser secured in a
Thorlabs SM1 mounting tube. A 390 nm OD6 band pass filter from Edmund optics
is placed at the end of the tube to isolate the laser line. A 450 nm
barrier filter (FELH0450 from Thorlabs) is introduced in the column of
the microscope to avoid the UV light in pictures or spectra. A 150 mm
or 100 mm focal length lens can be screwed at the apex of the tube to
focus the light for reflection spectra or images recording.
The right source has been build around a UV LED
365 nm wavelength (LZ4-04UV00
from LED ENGIN, see picture below). The LED is powered by a
ESS015W-0700-18-Z1 supply from ERP power. To remove the heat
generated by the LED, a radiator is attached on the LED mounting plate
and a small ventilator is used to cool down the assembly. A 370 nm band
pass filter (Edmund
placed inside the tube to remove all visible light from the source. A
ground glass diffuser in the tube is used to avoid the image of the LED
onto the microscope stage and thus to get an homogenous lightning of the
field of view. A 150 mm lens at the end of the tube focus the light on
the microscope stage. A 400 nm long pass filter (Thorlabs FEL 0400) is
introduced into the accessory slit of the microscope column to
completely remove the UV light from images or spectra.