Interference of light caused by thick film Koshi
Interference of light caused by thick film Koshi High School Keisuke Ueda Taisei Shibata Daichi Shiratsuka Ryohei Nakahashi
Interference of light interference・・・ reflected light in front of the film and reflected light in the back film overlap. Then light wave length and thickness of film affect the volume of light. As a result, light looks like stripe pattern
Example of Light interference caused by thin film in physics text book Interference of the thin films such as air or the liquid between two pieces of glassworks ・Film of soap bubble ・Newton’s rings
●In text book・・・ 「when a film become thick, stripe pattern can not be seen. 」 This is meaning that we can’t observe （数研出版 物理） “Thick film " and" White light " but If 「Thick film」 and 「Monochromatic light」 ?
Interference of the monochromatic light caused by thick film In the precedent study ■Widen a Na lamp and a laser beam, and use it ■Use Na lamp through the pinhole ■Expose light reflectors such as the paper to the light of the Na lamp and assume it a source of light By this experiment Use the natural expanse of the laser beam
Interference of light by the flat glass How to experiment Laser device He-Ne laser （638. 3 nm 5 m. W） Flat glass Between laser device and glass is over 2 m screen Interference version（6 mm） and Glass slide(1. 3 mm）
Interference of light by the flat glass Result Interference version（6 mm） Glass slide(1. 3 mm）
Interference of light by convex lens How to experiment 4ｍ
Interference of light by convex lens About lens 1 Focus length 200 mm turn off the light Use graph paper as a screen Convex lens diameter 750 mm
Interference of light by convex lens About lens 1 Dark circle diameter Bright circle diameter 1 10. 2 18. 7 2 25. 7 30. 3 3 34. 7 40. 0 4 40. 3 46. 0 5 48. 7 52. 7
Interference of light by convex lens 1 lens 2 lens 3 Focus length 200 mm Convex lens diameter 750 mm Focus length 250 mm Convex lens diameter 750 mm Focus length 300 mm Convex lens diameter 750 mm 1 2 3 4 5 Dark circle 10. 2 25. 7 34. 7 42. 7 48. 7 Bright circle 18. 7 30. 3 40. 0 46. 0 52. 7 1 2 3 4 5 Dark circle 14. 7 26. 7 34. 7 40. 3 44. 7 Bright circle 20. 0 26. 7 37. 3 42. 0 46. 7 1 2 3 4 5 Dark circle 15. 0 25. 0 33. 0 39. 0 44. 0 Bright circle Unit : mm 20. 0 28. 7 35. 8 41. 7 47. 0
Conclusion We can observe interference of light by thick film. Things to do We will consider about light line.
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