Wavelength shifts of dye lasing in microdroplets: effect of absorption change

Mazumder, Md. Mohiuddin; Chen, Gang; Chang, Richard K.; Gillespie, James B.

doi:10.1364/ol.20.000878

Cited by 33 publications

(18 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Opposing trends of quality factor and lasing threshold are observed reflecting the interrelated behavior of these quantities. 45 Also consistent with the latter findings is the observation that the gap size influences the spectral position of the WGM lasing. As illustrated in Fig.…”

Section: A Split-disk Micro-cavities-an Alternative Wgm Geometrysupporting

confidence: 71%

“…This behavior can again be linked to the change in cavity Q-factor and is a well-understood phenomenon. Such blue shifts are well documented in dye-based micro-lasers for increasing absorption 45 or radiation losses. 32,46,47 In the presented work losses affecting the quality factor are due to the decreasing confinement in the gap region [see Fig.…”

Section: A Split-disk Micro-cavities-an Alternative Wgm Geometrymentioning

confidence: 89%

See 1 more Smart Citation

Split-disk micro-lasers: Tunable whispering gallery mode cavities

et al. 2017

View full text Add to dashboard Cite

Optical micro-cavities of various types have emerged as promising photonic structures, for both the investigation of fundamental science in cavity quantum electrodynamics and simultaneously for various applications, e.g., lasers, filters, or modulators. In either branch a demand for adjustable and tunable photonic devices becomes apparent, which has been mainly based on the modification of the refractive index of the micro-resonators so far. In this paper, we report on a novel type of whispering gallery mode resonator where resonance tuning is achieved by modification of the configuration. This is realized by polymeric split-disks consisting of opposing half-disks with an intermediate air gap. Functionality of the split-disk concept and its figures of merit like low-threshold lasing are demonstrated for laser dye-doped split-disks fabricated by electron beam lithography on Si substrates. Reversible resonance tuning is achieved for split-disks structured onto elastomeric substrates by direct laser writing. The gap width and hence the resonance wavelength can be well-controlled by mechanically stretching the elastomer and exploiting the lateral shrinkage of the substrate. We demonstrate a broad spectral tunability of laser modes by more than three times the free spectral range. These cavities have the potential to form a key element of flexible and tunable photonic circuits based on polymers.

show abstract

Section: A Split-disk Micro-cavities-an Alternative Wgm Geometrysupporting

confidence: 71%

Section: A Split-disk Micro-cavities-an Alternative Wgm Geometrymentioning

confidence: 89%

Split-disk micro-lasers: Tunable whispering gallery mode cavities

et al. 2017

View full text Add to dashboard Cite

show abstract

“…This is accompanied by a decrease of the lasing thresholds due to an increased concentration of dye molecules within the WGMs. These effects can be described by a modified standard dye laser model [11,20], where the number of dye molecules per mode volume depends on the thickness of the gain layer.…”

Section: Lasing In Organic Semiconductor Coated Microgobletsmentioning

confidence: 99%

Strongly confined, low-threshold laser modes in organic semiconductor microgoblets

Großmann¹,

Klinkhammer²,

Floess³

et al. 2011

Opt. Express

View full text Add to dashboard Cite

Abstract:We investigate lasing from high-Q, polymeric goblet-type microcavities covered by an organic semiconductor gain layer. We analyze the optical modes in the high-Q cavities using finite element simulations and present a numerical method to determine the cutoff thickness of the gain layer above which the whispering gallery modes are strongly confined in this layer. Fabricated devices show reduced lasing thresholds for increasing gain layer thicknesses, which can be explained by a higher filling factor of the optical modes in the gain layer. Furthermore, reduced lasing threshold is accompanied by a red-shift of the laser emission.

show abstract

“…We consider a simple model of dye-lasing. 69,70 We assume that the fluorescentdye molecule can be approximated as a 4-level system. Let rai be the number density (per unit volume) of molecules in the first excited electronic singlet and n 0 be the number density of molecules in the ground electronic singlet state.…”

Section: Dye Lasing In Microdropletsmentioning

confidence: 99%

“…ni<T.(A) > CtleakageW + <Xab,(\, T) + n0<Ta(X), (69) where a; eo t" se is the leakage loss out of the cavity and a a b, is the absorption loss of the liquid and any additive. The absorption and the stimulated emission cross-sections of the dye are <r" and <r e , respectively.…”

Section: Dye Lasing In Microdropletsmentioning

confidence: 99%

Optical Resonances of a Spherical Dielectric Microcavity: Effects of Perturbations

Mazumder¹,

Chowdhury²,

Hill³

et al. 1996

Optical Processes in Microcavities

Self Cite

View full text Add to dashboard Cite

The resonances of a dielectric microsphere (morphology-dependent resonances (MDR's), whispering gallery modes, or quasinormal modes) have extremely large (>10 6 ) quality factors (Q's) even when the sphere is as small as a few wavelengths. Perturbations in the refractive index or the shape of a microsphere shift the resonance frequencies and change the Q's from those of the unperturbed sphere. Here we develop an effective-average model to compute the first-order perturbation-induced changes in the resonance frequencies and the Q's of the MDR's. Near or on a resonance, a modified definition of mode volume is used to approximate the microsphere as a closed cavity. Analogous to the modal gain or loss in a waveguide cavity, an effective-average modal gain or loss in an inhomogeneous microsphere is defined. Both the effective-average and a time-independent perturbation theory are used to model optical bistability in a dielectric microsphere. Dispersive and absorptive optical bistability result from intensity-dependent perturbations in the real and the imaginary part of the refractive index, respectively. The effect of perturbations (e.g., size changes, shape deformations, and temperature-dependent absorption) on the dye-lasing spectra from liquid microdroplets are discussed. We show that perturbation effects can be used to develop optical diagnostics for the determination of droplet properties such as evaporation rate, shape deformation, surface tension, and temperature.

show abstract

Wavelength shifts of dye lasing in microdroplets: effect of absorption change

Cited by 33 publications

References 7 publications

Split-disk micro-lasers: Tunable whispering gallery mode cavities

Split-disk micro-lasers: Tunable whispering gallery mode cavities

Strongly confined, low-threshold laser modes in organic semiconductor microgoblets

Optical Resonances of a Spherical Dielectric Microcavity: Effects of Perturbations

Contact Info

Product

Resources

About