Tunable add-drop filter using an active whispering gallery mode microcavity

An add-drop filter (ADF) fabricated using a whispering gallery mode resonator has different crosstalks for add and drop functions due to non-zero intrinsic losses of the resonator. Here, we show that introducing gain medium in the resonator and optically pumping it below the lasing threshold not only allows loss compensation to achieve similar and lower crosstalks but also tunability in bandwidth and add-drop efficiency. For an active ADF fabricated using an erbium-ytterbium co-doped microsphere, we achieved 24-fold enhancement in the intrinsic quality factor, 3.5-fold increase in drop efficiency, bandwidth tunability of 35 MHz and a crosstalk of only 2%.

[1]  J. Kalkman,et al.  Demonstration of an erbium doped microdisk laser on a silicon chip , 2006, 2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference.

[2]  A. Scherer,et al.  Low-Threshold Photonic Crystal Laser , 2002 .

[3]  K. Vahala,et al.  Fiber-optic add-drop device based on a silica microsphere-whispering gallery mode system , 1999, IEEE Photonics Technology Letters.

[4]  A. Yariv,et al.  All-fiber zero-insertion-loss add-drop filter for wavelength-division multiplexing. , 1998, Optics letters.

[5]  G. Farca,et al.  Microsphere whispering-gallery-mode laser using HgTe quantum dots , 2004 .

[6]  Lan Yang,et al.  Whispering gallery microcavity lasers , 2013 .

[7]  Shibin Jiang,et al.  2μm lasing from highly thulium doped tellurite glass microsphere , 2005 .

[8]  Lan Yang,et al.  A Robust and Tunable Add–Drop Filter Using Whispering Gallery Mode Microtoroid Resonator , 2012, Journal of Lightwave Technology.

[9]  Lan Yang,et al.  Gain-Induced Evolution of Mode Splitting Spectra in a High- $Q$ Active Microresonator , 2010, IEEE Journal of Quantum Electronics.

[10]  K. Vahala,et al.  Fiber-coupled microsphere laser. , 2000, Optics letters.

[11]  M. S. Abrishamian,et al.  Three output port channel-drop filter based on photonic crystals. , 2009, Applied optics.

[12]  K. Vahala,et al.  Ultralow-threshold Raman laser using a spherical dielectric microcavity , 2002, Nature.

[13]  Umar Mohideen,et al.  GaAs/AlGaAs microdisk lasers , 1994 .

[14]  D. Gill,et al.  Very high-order microring resonator filters for WDM applications , 2004, IEEE Photonics Technology Letters.

[15]  Jelena Vuckovic,et al.  Enhanced light emission in photonic crystal nanocavities with Erbium-doped silicon nanocrystals , 2008 .

[16]  K. Vahala,et al.  Gain functionalization of silica microresonators. , 2003, Optics letters.

[17]  Kerry J. Vahala,et al.  Fiber-coupled erbium microlasers on a chip , 2003 .