Time filter

Source Type

Zhu Z.,Sun Yat Sen University | Zhu Z.,Shandong Huaguang Optoelectronics Co. | Zhang X.,Shandong Huaguang Optoelectronics Co. | Li P.,Shandong Huaguang Optoelectronics Co. | And 3 more authors.
Journal of Semiconductors | Year: 2015

GaInAsP layers and GaAsP/ (Al) GaInP laser diodes (LDs) have been grown on GaAs substrates by metalorganic chemical vapor deposition. The GaInAsP layer, which is lattice matched to GaAs, has an intermediate band gap between Ga0:5In0:5P and GaAs. The GaInP/GaAs heterojunction spikes, especially in the valence band, can be suppressed by introducing this thin GaInAsP layer into the heterostructure interface. The 808 nm GaAsP/ (Al) GaInP LDs with GaInAsP intermediate layer show a reduced operating voltage compared to the conventional LDs with abrupt GaInP/GaAs interface due to the enhanced hole injection. As a result, the power conversion efficiency is improved from 52% to 60% at 350 mW output power. At high current injection, the LD with GaInAsP intermediate layer has higher light power owing to the decreased joule heating. © 2015 Chinese Institute of Electronics. Source

Bi Z.-F.,Shandong University | Wang L.,Shandong University | Liu X.-H.,Shandong University | Zhang S.-M.,Shandong University | And 4 more authors.
Optics Express | Year: 2012

We report on the formation and the optical properties of the planar and ridge optical waveguides in rutile TiO2 crystal by He+ ion implantation combined with micro-fabrication technologies. Planar optical waveguides in TiO2 are fabricated by high-energy (2.8 MeV) He +-ion implantation with a dose of 3 × 1016 ions/cm2 and triple low energies (450, 500, 550) keV He +-ion implantation with all fluences of 2 × 1016 ions/cm2 at room temperature. The guided modes were measured by a modal 2010 prism coupler at wavelength of 1539 nm. There are damage profiles in ionimplanted waveguides by Rutherford backscattering (RBS)/channeling measurements. The refractive-index profile of the 2.8 MeV He+- implanted waveguide was analyzed based on RCM (Reflected Calculation Method). Also ridge waveguides were fabricated by femtosecond laser ablation on 2.8 MeV ion implanted planar waveguide and Ar ion beam etching on the basis of triple keV ion implanted planar waveguide, separately. The loss of the ridge waveguide was estimated. The measured near-field intensity distributions of the planar and ridge modes are all shown. © 2012 Optical Society of America. Source

Gong H.,Shandong University | Gong H.,University of Jinan | Hao X.,Shandong University | Wu Y.,Shandong University | And 4 more authors.
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2011

Photonic crystal (PhC) structure is an efficient tool for light extraction from light-emitting diodes (LEDs). The fabrication of a large area PhC structure on the light output surface of LEDs often involves sophisticated equipments such as nanoimprint lithography machine. In this study a monolayer of polystyrene (PS) microspheres was employed as a template to fabricate a noninvasive photonic crystal of indium tin oxide (ITO) on the surface of GaN-based LED. PS spheres can help to form periodic arrangement of bowl-like holes, a photonic crystal with gradually changed fill factors. Importantly, the electroluminescence intensity of LED with a photonic crystal was significantly enhanced by 1.5 times compared to that of the conventional one under various forward injection currents. © 2011 Elsevier B.V. All rights reserved. Source

Gong H.-B.,Shandong University | Hao X.-P.,Shandong University | Xia W.,Shandong University | Xia W.,Shandong Huaguang Optoelectronics Co. | And 3 more authors.
Guangdianzi Jiguang/Journal of Optoelectronics Laser | Year: 2010

After inductively coupled plasma etching using Indium Tin oxide(ITO) particles as mask, we manufactured red-light-emitting diode(LED) that surface roughened and investigated the effect of etching duration to ITO on LED surface morphology. The results showed that under the inject current of 20 mA, the light extraction efficiency of surface roughened LED increased by at least 30% when the diameter of the formed GaP particles was around 200~500 nm and the etching depth is 200~400 nm. In addition, surface roughening did not have any effect on the angular distribution of emitted light. Source

Yu G.-L.,Shandong University | Yu G.-L.,Shandong Huaguang Optoelectronics Co. | Hu X.-B.,Shandong University | Xu X.-G.,Shandong University | Xu X.-G.,Shandong Huaguang Optoelectronics Co.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2015

A compression method of the fast axis of semiconductor laser by micro lens using optical fiber is introduced. By coating the two symmetrical sides of the fiber with antireflection films, the light reflection of the micro lens using optical fiber is reduced from original 4% to less than 0.3%, which effectively avoids the formation of external cavity. This method eliminates the formation of the side peak in the wavelength spectrum caused by the compression of the fast axis, which is beneficial to the application of the low-cost civil lasers. © 2015, Chinese Ceramic Society. All right reserved. Source

Discover hidden collaborations