Microcavity resonator

Blom, F.C., vanDijk, D.R., Hoekstra, H.J.W.M., Driessen, A., and Popma, T.J.A., 1997, Experimental study of integrated-optics microcavity resonators Toward an all-optical switching device., Appl. Phys. Lett. 71(6) 747-749. 

A DNA biosensor based on various porous silicon layers was fabricated using an oxidized microcavity resonator design developed by Chan et al. [37], the porous sihcon containing silicon nanocrystals that can luminescence efficiently in the visible. 

As has been pointed out above, a laser basically consists of an active material and a resonator. The latter enables the build-up of certain resonant modes and essentially determines the lasing characteristics. In most conventional devices, the optical feedback is provided by an external cavity with two end mirrors forming the resonator. With the advent of polymers as active materials, various new feedback structures were invented. Initially, a microcavity resonator device of the type shown schematically in Fig. 6.13 a was employed [48]. 

Chen C.H., Kelder E.M., Schoonman J. Unique porous LiCo02 thin layers prepared by electrostatic spray deposition. J. Mater. Sci. 1996 31 5437-5442 Chen C.H., Kelder E.M., Schoonman J. Electrostatic sol-spray deposition (ESSD) and characterisation ofnanostructured Ti02 thin films. Thin Solid Films 1999 342 35-41 Chen K.M., Sparks A.W., Luan H.C., Lim D.R., Wada K., Kimerling L.C. Si02/Ti02 omnidirectional reflector and microcavity resonator via the sol-gel method. Appl. Phys. Lett. 1999 75 3805-3807... 

Figure 13-9. (a) TEM images of a Ti02/Si02 omnidirectional reflector (top) and a microcavity resonator (bottom), both of which were fabricated by the sol-gel process, and (b) angle-dependent reflectance spectra of the omnidirectional reflectorfor both TE and TM modes (solid curves observed, dotted curves calculated) (Chen, 1999). 

Fig. 51 Transmission spectra of the defect-free and defect-contained PhC logpile structures. The appearance of a sharp peak was assigned due to PhC microcavity resonance...

Formation of the PEG and microcavity resonance was also confirmed by numerical modeling. Figure 52 shows the transmission spectra of reference (a) and defected (b) samples, calculated using the transfer-matrix technique. Transmission for TE (broken line) and TM (solid line) linearly polarized modes was considered separately in anticipation that the absence of some oriented rods in the defected sample would result in different conditions for the propagation of TE and TM modes. The calculated transmission spectrum of the reference sample is shown in Fig. 52a. 

Spectral positions of the calculated transmission dips are close to those observed experimentally, but the calculated dips are somewhat deeper and broader (gap to midgap ratio is about 9%). A similar result is obtained for the defected sample (Fig. 52b), but in this case a distinct peak within the dip, marking the microcavity resonance, is seen for each polarization. The peaks are centered at 3.801 m (TM) and 3.838 [im (TE), have Lorentzian line shapes, and almost identical amplitudes (about 16%) and Q-factors (about 85). As expected, there is a slight displacement between the peaks of different polarizations due to the anisotropic nature of the defect. Transmission at the maximum of the resonance peak is about 16%. Altogether, the numeric simulations qualitatively reproduce the experimental data, routine-... 

Consider a microcavity in which light is coupled into a WGM from an adiabatically tapered fiber tangentially in contact with the resonator. Tunable single-frequency... 

Fig. 5.1 Four mirror ring cavity model. Left, microcavity and tapered fiber in contact. Light can couple from the fiber into the resonator and back into the fiber. Right, the four mirror ring cavity equivalent. The top mirror is partially transmitting all others have 100% reflectivity. Reprinted from Ref. 3 with permission. 2008 Optical Society of America...

Vollmer, F. Braun, D. Libchaber, A. Khoshsima, M. Teraoka, I. Arnold, S., Protein detection by optical shift of a resonant microcavity, Appl. Phys. Lett. 2002, 80, 4057 4059... 

The top-emitting OLED with a bilayer anode of Ag/CFX and an ultrathin Ag layer used in the upper semitransparent cathode forms an optical microcavity, which can tailor the spectral characteristics of the emitters therein by allowing maximum light emission near the resonance wavelengths of an organic microcavity [80,81], When the mode wavelength of the cavity is fixed at 550 nm, the thickness of the Ph-PPV layer is determined to be about 110 nm [81]. 

Other types of optical microcavities employing the DBR mechanism of light confinement include planar annular Bragg resonators (Scheuer, 2005), based on a radial defect surrounded by Bragg reflectors, and their 3-D equivalent, spherical Bragg onion resonators (Liang, 2004). 

It should be noted, however, that the Q factors of open microcavities do not characterise directly the threshold gain values of the corresponding semiconductor lasers. To overcome this difficulty a new lasing eigenvalue problem (LEP) was introduced recently (Smotrova, 2004). The LEP enables one to quantify accurately the lasing frequencies, thresholds, and near- and far-field patterns separately for various WG modes in semiconductor laser resonators. However, the threshold of a lasing mode depends on other... 

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