Single lens dual optical systems.
There are already in the market some very good motorized zoom lens that cover a high enough focal length allowing them to be used as spotter and resolver at the same time.
For example the Computar H27Z1970AMS that goes from 19mm to 513mm, by using a 1/4"( 4 mm ) HD board camera in prime focus will give an optical magnification of 120x, that will be very good for resolving the structure of many anomalies, using a 2x focus extender will duplicate that.
Now the detail is how do we switch from infrared spotting to optical, normal viewing?
Many of today's security cameras boars have a cutoff mechanism that place an infrared cutoff filter in front of the ccd/cmos sensor in daylight viewing and switch off that cutoff infrared filter in nighttime viewing mode, exactly the same as the night shot option on some camcorders.
Then the solution is to modify that cutoff mechanism in such a way that when the cutoff filter is off then an infrared pass filter of 850nm or 950nm is placed in front of the ccd/cmos sensor.
In that way when scanning in infrared the infrared pass filter is used and when switching to normal viewing the cutoff filter is then used.
That will be a very simple and effective dual optical system using a single lens.