High quality factor nanophotonic resonators in bulk rare-earth doped crystals

Abstract

Numerous bulk crystalline materials exhibit attractive nonlinear and luminescent properties for classical and quantum optical applications. A chip-scale platform for high quality factor optical nanocavities in these materials will enable new optoelectronic devices and quantum light-matter interfaces. In this article, photonic crystal nanobeam resonators fabricated using focused ion beam milling in bulk insulators, such as rare-earth doped yttrium orthosilicate and yttrium vanadate, are demonstrated. Operation in the visible, near infrared, and telecom wavelengths with quality factors up to 27,000 and optical mode volumes close to one cubic wavelength is measured. These devices enable new nanolasers, on-chip quantum optical memories, single photon sources, and non-linear devices at low photon numbers based on rare-earth ions. The techniques are also applicable to other luminescent centers and crystal. Fischer, S. Gsell, M. Schreck, and C. Becher, "One-and two-dimensional photonic crystal microcavities in single crystal diamond," Nat. Nanotechnol. 7(1), 69-74 (2011). #256023Received 28

Nondestructive photon detection using a single rare-earth ion coupled to a photonic cavity

“…2. High-quality resonators which are capable of coupling to a single rare-earth ion have recently been developed [24]. The cavity has a mode volume of V = (λ/n Y V O ) 3 = 0.064 μm 3 (where λ = 879.7 nm is the Nd linewidth and n Y V O = 2.2 is the refractive index of the YVO 4 crystal) and a quality factor of Q = 20 000.…”

“…There is no reason that cavities cannot be improved to reach higher quality factors; in [24] the theoretically possible quality factor is Q = 300 000 with the same mode volume V = (λ/n Y V O ) 3 . Then κ = 2π × 565 MHz, and the cavity-photon coupling is still g = 2π × 30.6 MHz.…”

Towards an efficient nanophotonic platform integrating quantum memories and single qubits based on rare-earth ions

“…[16][17][18][19][21][22][23] The triangular nanobeam has a width of 690 nm. 31 (11 on one side of the cavity defect mode and 20 on the other side) periodic subwavelength grooves of 147 nm along the beam axis were milled on top of the nanobeam.…”

“…The period of the grooves were modulated quadratically over 14 grooves to form defect modes in the photonic bandgap. 17 The fundamental TM mode, with top, side views shown in Fig. 1c, is chosen because it aligns with the strongest Nd dipole of the 879.8 nm transition along c axis of YVO crystals.…”

Coupling erbium dopants in yttrium orthosilicate to silicon photonic resonators and waveguides

“…It has been shown in theory and experiment that optical resonators can increase the coupling strength between the optical field and the ions [12,13]. Using small cavities [14] and large ensembles, the strong coupling regime can be reached [15]. Furthermore, impedance matching the input coupling rate of a cavity with negligible intrinsic loss to the collective absorption rate of the ions should engender optical memories with high efficiency [16].…”