DYNAMIC FOCAL SHIFT TYPE OPTICAL INTERFERENCE TOMOGRAPHIC MICROSCOPE

PROBLEM TO BE SOLVED: To provide a dynamic focal shift type optical interference tomographic microscope which is high-resolution, high-speed and inexpensive and uses an optical interference tomographic method.SOLUTION: A laser light whose wavelength is swept enters a single-mode fiber 101. The incident light is divided by a fiber coupler 102, and one moves toward an object to be measured 120 while the other is reflected by a mirror 108 as a reference light. The light reflected in the object to be measured 120 passes through a lens 105, a variable-focal length lens 104 and a lens 103 and is reconnected to the single-mode fiber 101. At that time, an incident position of the single-mode fiber and a focal point within the object to be measured are confocal, and only a reflected light from a focal position out of all the reflected lights from the inside of the object to be measured 120 is reconnected to the single-mode fiber 101. The focal position can be changed with the use of the variable-focal length lens 104, and reflectance distribution in a depth direction can be obtained.