Abstract:
Speckle patterns are formed from scattered coherent lights which interfere each other when an object surface is illuminated by a coherent light. Speckles formed on the surface of biological object are called biospeckle. Laser Speckle Imaging (LSI) is a non-destructive imaging technique that can be used to detect the optical signal from biological tissue. A simple LSI system is consist of three main components, which are a laser as a light source, a sample, and a light detector. In this study, LSI system has been constructed using He-Ne laser as a light source, Fuji apples and Washington apples (Red Delicious) as samples and CMOS camera as detector. Angles of light incident on the samples were varied that was 30o, 45o, and 60o angles in order to know the optimum angle that gave the highest speckle patterns intensity. The speckle patterns represented by lever of gray value were analyzed using Image-J software. The result showed that the level of maximum gray value depended on the angle of illumination. The bigger the irradiation angle was the smaller the maximum of gray value. The maximum gray values Intensity Fuji apples were higher than Washington apples for each angle. The level of gray value maximum of speckle pattern apples at an angle of 30o consecutive were 127,6523 a.u for Fuji apples and 99,9951 a.u for Washington apples, at an angle of 45o were 111,0635 a.u for Fuji apples and 83,5215 a.u for Washington apples and at an angle of 60o were 102,8457 a.u for Fuji apples and 66,9639 a.u for Washington apples. That was because the surface of Fuji apples more roughers than Washington apples.
