Questions Techniques Fréquemment Posées

The most common adhesive we use for bonding our prisms is Norland NOA61. It is low-shrink (so the pieces won't move as it cures) and has excellent bonding strength for glass-to-glass. The adhesive is UV cured, so you'll need a UV source to make it stick. Once cured the adhesive is opaque to UV light but still works great if you are going to use the glued prism pair for visible or NIR applications, in other words, you can expect high transmission from 400 - 2000nm.

Yes. UV adhesives are optimized to cure under UV light. UV adhesives absorb UV light and pass the visible and IR portions of the spectrum. However, since sunlight and most room lights also emit in the UV, the adhesives will cure under these conditions. Please note that initial and full cure times will be considerably longer, because there will be less energy spread over a larger area then when compared to a UV curing light source.

The choice of adhesive depends upon your application. Adhesives can be classified into two groups: optically opaque adhesives and optically transparent adhesives.

Optically opaque adhesives are used when light is not going to be transmitted through the adhesive, such as when bonding a mirror to an aluminum mount. Milbond and Loctite® are two such adhesives. Milbond adhesive, for example, uses two bonding agents that, when combined, create the adhesive. There is also a decementing agent available for Milbond that allows the adhesive to be removed when necessary. These type of adhesives do not require UV light in order to cure.

Optically transparent adhesives allow light to transmit through and are commonly used to bond lenses together. The Norland and Summers lines are two such adhesives. When cured with a UV light source, the adhesive has a defined index of refraction which we list under the specifications of each adhesive. Please note that UV adhesives such as Summers and Norland do not come with decementing agents and are very difficult to break the adhesion once cured.

Light Absorbing Black-Out Material is not tested for vacuum environments and the adhesive is likely to outgas in vacuum environments.