In the annular optical resonator mirror of the annular

摘要

PROBLEM TO BE SOLVED: To easily extract a laser beam to the outside of a mirror by providing a slit on an electron orbital plane to drive an electron beam from the exterior, and forming an optical resonator so that the electromagnetic field mode generated in the optical resonator is not affected by the slit. ;SOLUTION: A barrel type optical resonator 1 is provided with a slit 2. The cylindrical coordinates (r, z) of the cross sectional shape of the barrel type optical resonator 1 are formed into a circular arc shape of r=ρ2/R+√ (R02-z2) or a parabolic shape of r=R-z2/(4R0), where ρ: electron orbit radius, R: radius of the barrel type optical resonator 1 on an electron orbit plane, R0=Rsin2θ, and cosθ=ρ/R. The intensity of the electromagnetic field becomes maximum on the electron orbit when the cross sectional shape (r) is the circular arc shape or the parabolic shape. The energy of the electromagnetic field is dispersed on the face of the barrel type optical resonator 1. Even when the slit 2 is opened at the center section of the barrel type optical resonator 1, it gives little effect.;COPYRIGHT: (C)2000,JPO