| 摘要 |
A gas discharge ring laser formed in a glass-ceramic block has a reduced bore section of diameter d for suppressing unwanted TEM modes. The invention makes use of the fact that the gain available from the excited gas of the laser cavity falls off near the walls of the cavity. Thus, the diameter of a portion of the tube enclosing the excited gas is made sufficiently small so that the gain available to both the TEM00 and TEM01 modes is reduced gradually to zero at the cavity wall. Because of the different light distribution in the two modes, the overall gain for the TEM01 mode is significantly less than for the TEM00 mode, thus preventing the TEM01 mode from oscillating. <IMAGE> |
