LED-pumped whispering-gallery laser

Abstract

A low-cost light-emitting diode (LED) is sufficient to pump a quasi-continuous-wave bidirectional high-Q whispering-gallery resonator laser made of Nd:YVO₄. This is remarkable because of the very limited spatial and spectral coherence of an LED. The LED, delivering up to 3.5 W, centered around 810 nm, is turned on in intervals of 100 µs duration, and for these periods a laser output exceeding 0.8 mW has been verified. Furthermore, 0.1-s-long laser pulses are demonstrated. To the best of our knowledge this is the first demonstration of an LED-pumped high-Q whispering-gallery laser. The concept can be extended easily to other laser active materials. A prospect is also to pump several of such lasers with a single LED

Review of biosensing with whispering-gallery mode lasers

“…WGM lasing thresholds at µW pump power levels and below have been demonstrated 33 – 35 . Lasing thresholds of nJ have been shown for spatially and temporally incoherent optical pumping 36 . WGM thresholds of µJ cm −2 have been demonstrated for pumping with a pulsed laser 37 .…”

Ultra‐Low Threshold Titanium‐Doped Sapphire Whispering‐Gallery Laser

“…WGLs have been demonstrated with resonators composed of gain material in different geometries such as toroids, [ 27,28 ] rings, [ 29–31 ] microspheres, [ 32–34 ] asymmetric resonators [ 35–38 ] and discs. [ 39,40 ] As opposed to fabricating a WGMR from an active material to achieve lasing, a passive WGMR can be coated with an active material . A continuous‐wave (cw) laser has been demonstrated by coating a polystyrene microsphere by Tm 3+ ‐doped energy‐looping nanoparticles.…”

“…WGLs have been demonstrated with resonators composed of gain material in different geometries such as toroids, [27,28] rings, [29][30][31] microspheres, [32][33][34] asymmetric resonators [35][36][37][38] and discs. [39,40] Titanium doped sapphire (Ti:sapphire) is a laser gain material with broad gain bandwidth benefiting from the material stability of sapphire. These favorable characteristics of Ti:sapphire have given rise to femtosecond lasers and optical frequency combs.…”

Ultra-low Threshold Titanium doped sapphire Whispering-gallery Laser

“…A WGMR laser is usually referred to as whispering gallery laser (WGL). WGLs have been demonstrated with resonators made of gain material of different shapes such as toroids [27,28], rings [29][30][31], microspheres [32][33][34], asymmetric resonators [35][36][37][38] and disks [39,40].…”