Topic
Extinction ratio
About: Extinction ratio is a research topic. Over the lifetime, 8541 publications have been published within this topic receiving 111908 citations.
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TL;DR: In this article, the enhancement in the filtering quality (Q) factor of an integrated micro-ring resonator (MRR) by embedding it in an integrated Fabry-Perot (FP) cavity formed by cascaded Sagnac loop reflectors was demonstrated.
Abstract: We propose and experimentally demonstrate the enhancement in the filtering quality (Q) factor of an integrated micro-ring resonator (MRR) by embedding it in an integrated Fabry-Perot (FP) cavity formed by cascaded Sagnac loop reflectors (SLRs). By utilizing coherent interference within the FP cavity to reshape the transmission spectrum of the MRR, both the Q factor and the extinction ratio (ER) can be significantly improved. The device is theoretically analyzed, and practically fabricated on a silicon-on-insulator (SOI) wafer. Experimental results show that up to 11-times improvement in Q factor, together with an 8-dB increase in ER, can be achieved via our proposed method. The impact of varying structural parameters on the device performance is also investigated and verified by the measured spectra of the fabricated devices with different structural parameters.
39 citations
TL;DR: A localized Zn-diffusion process based on MOVPE is reported on, which allows to reduce waveguide loss from 2 dB/cm to below 0.4dB/cm and is confirmed by fabrication of a 73 mm long spiral ring resonator.
Abstract: Generic InP foundry processes allow monolithic integration of active and passive elements into a common p-n doped layerstack. The passive loss can be greatly reduced by restricting the p-dopant to active regions. We report on a localized Zn-diffusion process based on MOVPE, which allows to reduce waveguide loss from 2 dB/cm to below 0.4 dB/cm. We confirm this value by fabrication of a 73 mm long spiral ring resonator, with a record quality factor of 1.2 million and an extinction ratio of 9.7 dB.
39 citations
TL;DR: The liquid level detection principle of cladding mode frustrated total internal reflection (CMFTIR) effect is proposed and significant enhancement of CMFTIR effect is realized through macro-bend coupling system in which the dark-field coupling phenomenon between two multimode polymer optic fibers is observed through experiment.
Abstract: The liquid level detection principle of cladding mode frustrated total internal reflection (CMFTIR) effect is proposed. The significant enhancement of CMFTIR effect is realized through macro-bend coupling system in which the dark-field coupling phenomenon between two multimode polymer optic fibers is observed through experiment. Especially twisted macro-bend coupling structure (TMBCS) is adopted to achieve stable coupling of two naked POF. The testing result showed that the dark-filed forward coupling efficiency reached 2‰ and the extinction ratio of the liquid level probe reached 4.18dB. Compared with existing optical fiber liquid level sensors, the TMBCS probe is simpler, robuster, and cheaper. In addition, the TMBCS has the potential for displacement or stress sensing.
39 citations
TL;DR: High-power operation of a single-mode, linearly polarized, broadband superfluorescent Fiber source has been achieved by using a two-stage cladding-pumped fiber configuration comprising a low power, single-ended, ytterbium-doped superfluorescent fiber seed source and a high-powerCladding-Pumped, polarization-maintaining, large-mode-area, yTterBium- doped amplifier pumped by a high -power diode source.
Abstract: High-power operation of a single-mode, linearly polarized, broadband superfluorescent fiber source has been achieved by using a two-stage cladding-pumped fiber configuration comprising a low power, single-ended, ytterbium-doped superfluorescent fiber seed source and a high-power cladding-pumped, polarization-maintaining, large-mode-area, ytterbium-doped amplifier pumped by a high-power diode source at 976nm The source yielded a maximum linearly polarized output of 106W with a slope efficiency of up to 67% with respect to the launched pump power and with a measured polarization extinction ratio of 135dB The wavelength spectrum of the superfluorescent source spanned the range continuously from ~1035 to 1100nm, and the bandwidth (FWHM) of the emission spectrum was 21nm The minimum seed power required for an output power over 100W was only 10mW, corresponding to an effective power gain in the amplifier stage of 40dB Single-spatial-mode operation with a beam propagation factor (M2)<11 was achieved by bending the amplifier fiber to a bend radius of ~8cm, without a significant reduction in output power
39 citations
TL;DR: In this paper, the asymmetric Fano resonance line shape of EMRS is generated by adding a microring inside and coupling with the outer ring to produce a nonlinear phase shift.
Abstract: In this paper, the Fano resonance in the “eye-like” microring resonator system (EMRS) is theoretically and experimentally investigated. The asymmetric Fano-resonance line shape of EMRS is generated by adding a microring inside and coupling with the outer ring to produce a nonlinear phase shift. The EMRS was fabricated on silicon-on-insulator wafer by the complementary metal-oxide-semiconductor compatible process. Compared to the conventional single-stage microring add-drop filter structure, the maximum sharpness of the transmission of the drop port is enhanced 3 times, and the drop port extinction ratio is increased by about 20 dB. The experimental results are in good agreement with the theoretical analysis.
39 citations