Abstract
We experimentally demonstrate continuous-wave ultraviolet emission through forth-harmonic generation in a millimeter-scale lithium niobate whispering-gallery resonator pumped with a telecommunicationcompatible infrared source. The whispering-gallery resonator provides four spectral lines at ultraviolet, visible, near-infrared and infrared, which are equally spaced in frequency via the cascaded-harmonic process and span a 2-octave frequency band. Our technique relies on a variable crystal poling and high transverse order of the modes for phase-matching and a resonator quality factor of over 10 7 to allow cascaded-harmonic generation up to the fourth-harmonic at input pump powers as low as 200mW. The compact size of the whispering gallery resonator pumped at telecommunicationcompatible infrared wavelengths and the low pump power requirement make our device a promising ultraviolet light source for information storage, microscopy, and chemical analysis.
| Original language | English |
|---|---|
| Pages (from-to) | 24139-24146 |
| Number of pages | 8 |
| Journal | Optics Express |
| Volume | 19 |
| Issue number | 24 |
| DOIs | |
| State | Published - 21 Nov 2011 |
| Externally published | Yes |