Theoretical study of annealed proton-exchanged Nd : LiNbO3 channel waveguide lasers with variational method

Citation
Dl. Zhang et al., Theoretical study of annealed proton-exchanged Nd : LiNbO3 channel waveguide lasers with variational method, J LIGHTW T, 19(10), 2001, pp. 1560-1568
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Optics & Acoustics
Journal title
JOURNAL OF LIGHTWAVE TECHNOLOGY
ISSN journal
0733-8724 → ACNP
Volume
19
Issue
10
Year of publication
2001
Pages
1560 - 1568
Database
ISI
SICI code
0733-8724(200110)19:10<1560:TSOAPN>2.0.ZU;2-G
Abstract
The controllable fabrication parameters, including anneal time, initial exc hange time, channel width, dependences of TM00 mode size, corresponding eff ective refractive index, effective pump area, and coupling efficiency betwe en pump and laser modes in z-cut annealed proton-exchanged (APE) Nd:LiNbO3 channel waveguide lasers were studied by using variational method. The effe ct of channel width on the surface index increment and the waveguide depth was taken into account. The features of mode size and effective refractive index were summarized, discussed, and compared with previously published ex perimental results. The effective pump area, which is directly proportional to threshold pump power, increases strongly, slightly, and very slightly w ith the increase of anneal time, channel width, and initial exchange time, respectively. However, the coupling efficiency, which is directly proportio nal to slope efficiency, remains constant (around 0.82) no matter what chan ges made to these parameters. The variation of the coupling loss between an APE channel waveguide and a fiber with these parameters for both laser (10 85 nm) and pump (815 nm) wavelengths was also calculated. The calculated re sults indicate that the coupling loss decreases rapidly, slightly and very slightly with the increase of anneal time, channel width and initial exchan ge time, respectively.