The contents on this page might come helpful sometime or other
http://halas.rice.edu/conversions for energy conversions
Few useful links on optics basics can be found by navigating through the following links. These are not exhaustive, there are many sources available.
https://www.edmundoptics.com/knowledge-center/#!&CategoryId=112 : Edmund optics
https://www.rp-photonics.com/encyclopedia.html : RP Photonics
https://www.newport.com/resourceListing/tutorials : New Port
The documents have been taken from various online sources