The process of cementing optical glass
1.The concave and convex lenses that are to be stuck together are wiped clean using lens paper soaked in cleaning liquid.
2.Optical adhesive is applied to the concave lens.
3.The convex lens is placed on top of the concave lens. At this stage numerous bubbles are visible in the cement layer (the adhesive).
4.Downward pressure is applied using a cork, and the bubbles are squeezed out of the adhesive. The pressure is carefully varied so that the convex lens does not touch the surface of the concave lens.
5.The lenses are then heated in an oven. The adhesive is hardened until it reaches a consistency that allows easy adjustment, forming a temporary joint.
6.Observing the lenses, which have been cemented together, through a microscope and rotating them to check if the centers of the two lenses are consistent. Fingertip pressure is then used to align the lens centers. This operation is known as "centering." The lenses are then left to stand overnight to allow the adhesive to harden.
7.The lenses are heated again in the oven, so as to fully harden the adhesive.