| 摘要 |
PROBLEM TO BE SOLVED: To provide a ring combiner having a progressively-varying numerical aperture (NA).SOLUTION: A waveguide comprises an annular cross-section 130 and a first numerical aperture (NA) at one end. The waveguide further comprises either an annular or circular cross-section 150 at the other end, which has a second NA. The waveguide has a progressively-varying NA, which varies from the first NA (at one end) to the second NA (at the other end). |
