'nonoptically' originates from Modern English, specifically the combination of the prefix 'non-' (from Latin 'non' meaning 'not') and the adjective 'optical' (from French 'optique' and Latin 'opticus'), where 'non-' meant 'not' and 'opticus/optikos' related to 'seeing' or 'sight'.

'optical' changed from Greek 'optikos' (ὀπτικός) to Latin 'opticus', then through Old French 'optique' into Middle/Modern English as 'optical'; adding the negative prefix 'non-' produced 'nonoptical', and finally the adverbial suffix '-ly' formed 'nonoptically'.

Initially the root meant 'related to seeing' or 'visible'; over time 'optical' came to refer to properties involving light and vision, and 'nonoptically' evolved to mean 'in a manner not using optical/visual techniques'.