News

February 21, 2019

Ryan Patton publishes research in Optics Letters

  • Ryan Patton and Ronald M. Reano, “Rotating polarization using Berry’s phase in asymmetric silicon strip waveguides,” Optics Letters 44, 1166-1169 (2019).
  • Abstract: Light propagating in an out-of-plane curvilinear waveguide acquires a Berry’s phase, which rotates optical polarization. The effect is promising for realizing waveguide polarization controllers. In high index contrast platforms, such as silicon-on-insulator, however, small waveguide cross-sectional asymmetries reduce the amount of polarization rotation. To overcome this, we present a method based on the periodic spatial modulation of Berry’s phase. Ninety degree polarization rotation is achieved, even in the presence of waveguide asymmetry. Using a numerical model based on Jones calculus, we demonstrate the approach with 303×300  nm squared asymmetric silicon waveguides. We convert polarization from transverse electric to transverse magnetic with a polarization extinction ratio (PER) greater than 20 dB PER over a 100 nm bandwidth in a 110×240 micrometer squared footprint.

February 3, 2019

Professor Reano gives invited talk at SPIE Photonics West in San Francisco, California

  • Ronald M. Reano, “Creating integrated optics with ion-sliced lithium niobate combined with patterned silicon or silicon nitride,” (Invited Paper) in Smart Photonic and Optoelectronic Integrated Circuits XXI, Paper 10922-25.
  • Abstract: Design, fabrication, and measurement aspects of integrated optic devices based on ion-sliced lithium niobate combined with patterned silicon or silicon nitride are presented. Two electro-optic devices are shown, namely, an RF electric-field sensor with a demonstrated sensitivity of 4.5 V/m per square root hertz and an electro-optic ring modulator with demonstrated digital modulation of 4.5 Gb/s. A device is also presented for quasi-phase matched second harmonic generation. Periodic poling of thin films of x-cut lithium niobate has been achieved with 7.5 micrometer poling period. Chip-scale electro-optics and nonlinear optics are envisioned for classical and quantum communications, sensing, and computing applications.

September 16, 2018

Ryan Patton presents at the Frontiers in Optics Conference in Washington DC

  • Ryan J. Patton and Ronald M. Reano, “Polarization rotation utilizing Berry’s phase in asymmetric silicon waveguides,” in Frontiers in Optics / Laser Science (FiO): 2018, OSA Technical Digest (online) (Optical Society of America, 2018), paper JW3A.2.
  • Abstract: We present a method to achieve polarization rotation in asymmetric silicon waveguides using Berry’s phase. By exploiting periodic in-plane and out-of-plane sections, we achieve 90° polarization rotation in the presence of linear birefringence.

July 25, 2018

Tyler Nagy presents at the Conference on Lasers and Electro-Optics in San Jose, California

  • Jonathan Tyler Nagy and R. M. Reano, “Periodic poling of ion-sliced x-cut magnesium oxide doped lithium niobate thin films,” in Conference on Lasers and Electro-Optics (CLEO): 2018, OSA Technical Digest (online) (Optical Society of America, 2018), paper SF2I.2.
  • Abstract: We fabricate and periodically pole 700 nm thick ion-sliced x-cut magnesium oxide doped lithium niobate thin films. Uniform domains with 50% duty cycle are imaged by piezo-response force microscopy.