摘要 |
<p>An optical oscillator has first (13) and second (14) resonant cavities with at least a portion of each cavity sharing a common volume. A characteristic of at least one of the cavities is variable. A non-linear material (20) is positioned within the 'common volume'. Variation of the or each resonant cavity enables a continuously tunable output signal to be obtained. The invention overcomes the problem associated with prior art systems in which phase matching, resonance of a common cavity at two wavelengths and energy conservation were required simultaneously.</p> |