The output of a laser is relatively directional, allowing high coupling efficiency ( 50 %) into single-mode fiber.
This back-reflection tolerance might be achieved using an optical isolator or by way of reduced coupling efficiency.
It demonstrated good coupling efficiency, and enough radiation efficiency.
In both cases the horn improves the coupling efficiency between the speaker driver and the air.
The Nova design was then modified into a smaller design that added frequency conversion to 351 nm light, which would increase coupling efficiency.
A precision translation stage (micro-positioning table) is used to move the lens, fiber, or device to allow the coupling efficiency to be optimized.
With good beams, 70 to 90% coupling efficiency can be achieved.
For example, the coupling efficiency of the light source is kept consistent between the initial and the cutback measurements.
However, the units operate with somewhat reduced coupling efficiency and so have reduced power compared to operation with ferrous cookware.
They could only manage a coupling efficiency in the region of 5-10%.