Secondary ion mass spectrometry study of Ti 4+ diffusion properties in congruent Er:LiNbO 3 codoped with moderate concen
- PDF / 615,026 Bytes
- 8 Pages / 584.957 x 782.986 pts Page_size
- 66 Downloads / 134 Views
i Chen Department of Opto-electronics and Information Engineering, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China; and Key Laboratory of Optoelectronics Information and Technical Science (Tianjin University), Ministry of Education, Tianjin, 300072, China
Liang Sun and Yu-Heng Xu School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, People’s Republic of China
Edwin Yue-Bun Pun Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong, People’s Republic of China (Received 1 April 2009; accepted 29 June 2009)
At 1100 C, the diffusion properties of Ti4+ into congruent LiNbO3 crystals codoped with 0.5 mol% Er2O3 and different MgO concentrations of 0.5, 1.0, and 1.5 mol% have been studied by secondary ion mass spectrometry (SIMS). Three Y-cut and three Z-cut plates with different Mg doping levels were coated with a 60-nm-thick Ti film at first and then annealed at 1100 C for 28 h in a wet O2 atmosphere. SIMS was used to analyze depth profile characteristics of diffused Ti ions and the constituent elements of the substrate as well. The results show that the diffusion reservoir was exhausted and the Ti metal film was completely diffused. All measured Ti profiles follow a Gaussian function. No Mg out-diffusion accompanied the Ti in-diffusion procedure for all crystals studied. The 1/e diffusion depth is similar to 8.3/10.2, 7.4/8.7, and 6.6/8.2 0.2/0.2 mm/mm for the Y/Zcut crystal with the Mg doping level of 0.5, 1.0, and 1.5 mol%, respectively, yielding a Ti4+ diffusivity of 0.62/0.93, 0.49/0.67, and 0.39/0.60 0.03/0.03 (mm2/h)/(mm2/h), respectively. The diffusion shows definite anisotropy and a considerable MgO doping level effect. Under the same Mg doping level, the diffusion in a Z-cut crystal is faster. The diffusivity decreases with the increase of the Mg doping level. This effect is qualitatively explained from the viewpoint of the Mg doping effect on concentration of the intrinsic defects in LiNbO3 crystal.
I. INTRODUCTION
Over the past 20 years, a family of Ti (vapor Zn)diffused Er:LiNbO3 waveguide lasers (amplifiers) and integrated devices have been demonstrated operating in infrared regime.1–10 Nevertheless, the photorefractive effect not only limits the choice for the pump and/or operation wavelength(s), but also affects the performance of these devices more or less. This detrimental effect (from a)
Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/JMR.2009.0393 J. Mater. Res., Vol. 24, No. 10, Oct 2009
http://journals.cambridge.org
Downloaded: 15 Mar 2015
the viewpoint of integrated optics application) is particularly serious in the visible regime and hence definitely restricts the applications in this region of spectrum. It is well known that doping with >5 mol% MgO can effectively improve the resistance to the optical damage.11,12 However, a large amount of MgO doping causes difficulty in growing Er/Mg-codoped sin
Data Loading...