- #1
thomasfox1
- 2
- 0
Hi,
I am a 17 year old college student from the UK carrying out an experiment to build a polarimeter to determine the specific rotation of sugars. However, I have a problem when I shine polarised light through my sucrose solution and turn the analyser polariser filter I see colours ranging from clear to yellow to blue and back again - rather than no light which I would expect when two polarisers are crossed. I have been researching for weeks to discover the root of this problem but I cannot find any mention of different colours! If possible, could you explain the theory as to why this works? I understand that chiral molecules rotate the plane of polarised light but I do not understand why I see different colours? As I haven't taken a physics A-level I find this very complicated. So far I have come across a number of things that may be to do with it (relevant or not). These are: ‘circular birefringence’, ‘circular dichroism’, ‘optical rotatory dispersion’, ‘left/right circularly polarised light’, ‘anisotropy’ and ‘isotropy’. I would appreciate a full explanation that isn't very complicated like some of the resources I find!. Thank you very much!
Tom
I am a 17 year old college student from the UK carrying out an experiment to build a polarimeter to determine the specific rotation of sugars. However, I have a problem when I shine polarised light through my sucrose solution and turn the analyser polariser filter I see colours ranging from clear to yellow to blue and back again - rather than no light which I would expect when two polarisers are crossed. I have been researching for weeks to discover the root of this problem but I cannot find any mention of different colours! If possible, could you explain the theory as to why this works? I understand that chiral molecules rotate the plane of polarised light but I do not understand why I see different colours? As I haven't taken a physics A-level I find this very complicated. So far I have come across a number of things that may be to do with it (relevant or not). These are: ‘circular birefringence’, ‘circular dichroism’, ‘optical rotatory dispersion’, ‘left/right circularly polarised light’, ‘anisotropy’ and ‘isotropy’. I would appreciate a full explanation that isn't very complicated like some of the resources I find!. Thank you very much!
Tom