I’d like to adhere two prisms together, how can I effectively achieve this? Is there a specific adhesive that you recommend?

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.