Mach-Zehnder interferometer that can be observed transmitted wavefront of the glass substrate of about 1mm.
By using a base of D-TOP, it shortens the distance to the imaging lens from the sample and is imaged an enlarged image of the sample onto the camera.
Images captured by the camera can be taken directly to a PC via USB and kept on record about stop and moving images.
In addition, it allows to adjust the brightness of the laser by using two polarizing plates and to be observed in the best image without saturation.

It is a device that uses an interferometer and measures the radius of curvature of the concave surface of the small curvature.
There are two positions where can be observed interference fringes reflected on the concave surface.
One position is that the focus is on a concave surface of the achromatic lens, and the other position is that the focus is on the center of curvature of the concave surface.When reading the micrometer on the stage carrying the sample, the distance between the two positions can be observed the interference fringes of concave sample, and it can be used to determine the precise radius of curvature.

As a polarizing Michelson interferometer using PBS and 1/4 wave plate,we have measured the coherent length of the background light of the semiconductor laser.
First, it takes the alignment of the interferometer in the He-Ne laser and retracts mirrors on the stage, and then collimating light of the semiconductor laser is incident to the interferometer. After removing the laser light by the polarizing plate, the semiconductor laser is observed only the background light by the camera.
By adjusting the movable mirror little by little, it can be found the position that the interference fringes appear.
The length of the range that is visible the interference fringes will be coherent length.