Two measurement geometries, allowing different experiments in the lab
I designed, then built two photoluminescence measurement setups for semiconductor samples. Both configuration used a white light source coupled to a monochromator, allowing to illuminate the sample under different (VIS) wavelengths. One configuration included an integrating sphere, which allowed to measure an absolute measurement of all the PL emitted from a sample. The other was a setup with a free space optical path, that enabled working with horizontal samples as well as vertical samples (The mirror turned with a hand knob). The goal was to make accurate optical characterization setups, that with sample placement that is easier to repeat, comparable and maintainable.
CAD overview of the measurement setup.
Free space PL measurement setups (for both Horizontal and Vertical samples)
PL measurements setups available in the market are directed specifically at hard semiconductor samples. My design allowed to turn the illuminating beam sideways to allow for vertical samples (i.e. a sample in liquid) To be measured under the same setup. The emitted light is collected back in the same path using an optical fiber.
Free space PL setup with horizontal sample (left) and vertical sample (right) configurations. The setup could accept the sample holder from the sphere.
Schematics, CAD design, build and under illumination. Integrating sphere setup (left), Free space setup (right).
2D drawing of a part designed for holding the x-y stage for the free-space setup:
