Determination of optical properties of normal and adenomatous human colon tissues in vitro using integrating sphere techniques

Figure 1 Experimental set-up consisting of double- integrating-sphere with an intervening sample. 1. Laser 2. Attenuator 3. Attenuator 4. 2 mm pinhole 5. Beam expander 6. 6 mm pinhole 7. Integrating sphere 8. Sample 9. Integrating sphere 10. Photodiode detector 11. Photodiode detector 12. Photodiode detector 13. Switch box 14. Lock-in-amplifier 15. Light chopper 16. PC.