Light conversion device with high uniformity

A measurement device, comprising:

• at least one light source configured to emit blue light;
• a light conversion device arranged such that the blue light emitted by the at least one light source is incident upon the light conversion device, which is configured to convert the blue light from the at least one light source into white light, the light conversion device comprising:
• a light conversion subassembly comprising at least one light conversion layer disposed between two light transmitting members, wherein the light conversion layer comprises a light conversion material comprising phosphors and/or quantum dots, and wherein the light conversion layer is configured to generate the white light from the incident blue light;
• at least one light diffusing subassembly adjacent the light conversion subassembly;
• and
• a top frame and a bottom frame at least bordering the at least one light diffusing subassembly and the light conversion subassembly, respectively;
• a sample holder configured to retain a sample such that the white light is directed into and at least partially through the sample;
• and
• a light detector configured to receive light that passes through the sample.