Comment on “Spontaneous Emission of Organic Molecules Embedded in a Photonic Crystal”

Abstract

Comment on "Spontaneous emission of organic molecules embedded in a photonic crystal", Megens, M.; Schriemer, H.P.; Lagendijk, A.; Vos, W.L.

An experimental study of strongly modified emission in inverse opal photonic crystals

“…[22]), and may be simply understood from a consideration of the number of simultaneously excluded modes as a function of frequency. Indeed, from a simple angle-dependent stop-gap consideration one expects that the blue edge of the L-gap corresponds to the frequency for which the largest fraction of solid angle is simultaneously contained in a stop gap [33,53]. The shift of the inhibition to higher frequency with smaller lattice parameter confirms that the spectral changes are due to the photonic crystal properties.…”

Weak photonic band gap effect on the fluorescence lifetime in three-dimensional colloidal photonic crystals

“…[4][5][6][7][8][9] The observed lifetime is generally composed of two parts: one is due to the spontaneous emission of electronic excited states, the other is caused by other nonradiative internal processes in molecules. The corresponding decay rates can be denoted as ⌫ϭ1/ r and 1/ nr , respectively.…”

“…The controversy has continued until now. 9 To verify to what extent the PBG effect is pure, we calculate the DOS and the function ( ,r) for the three samples. The DOS and the average of ( ,r) over different molecular positions, denoted as ͗ ( ,r)͘, are plotted in Fig.…”

“…[1][2][3][4][5][6][7][8][9] Martorell and Lawandy reported the first observation of inhibited spontaneous emission ͑SE͒ of dye molecules in dilute colloidal crystals composed of polystyrene microspheres in water. 4 They found a single exponential decay of the excited state and a variation of the fluorescence lifetime of 1.75 times.…”

“…1 In the last decade, there appeared great interest in controlling the spontaneous emission rate via threedimensional ͑3D͒ photonic crystals, [2][3][4][5][6][7][8][9][10][11][12] which are artificial periodic materials. It was suggested that if the atomic transition frequency lies inside the photonic band gap ͑PBG͒, the spontaneous emission will be completely inhibited, 2 as there is no photon mode that can perturb atomic states.…”