Nonlinear optical properties of free standing films of PbS quantum dots in the nonresonant femtosecond regime

Pushpa Ann Kurian; C. Vijayan; Amit Nag; Debabrata Goswami

doi:10.1117/12.733034

17 September 2007 Nonlinear optical properties of free standing films of PbS quantum dots in the nonresonant femtosecond regime

Pushpa Ann Kurian, C. Vijayan, Amit Nag, Debabrata Goswami

Author Affiliations +

Proceedings Volume 6639, Nanophotonic Materials IV; 66390M (2007) https://doi.org/10.1117/12.733034
Event: NanoScience + Engineering, 2007, San Diego, California, United States

Abstract

Devices based on optical technology for high speed communication networks require materials with large nonlinear optical response in the ultrafast regime. Nonlinear optical materials have also attracted wide attention as potential candidates for the protection of optical sensors and eyes while handling lasers. Optical limiters have a constant transmittance at low input influence and a decrease in transmittance at higher fluences and are based on a variety of mechanisms such as nonlinear refraction, nonlinear scattering, multiphoton absorption and free carrier absorption. As we go from bulk to nanosized materials especially in the strong quantum confinement regime where radius of the nanoparticle is less than the bulk exciton Bohr radius, the optical nonlinearity is enhanced due to quantum confinement effect. This paper is on the ultrafast nonresonant nonlinearity in free standing films of PbS quantum dots stabilized in a synthetic glue matrix by a simple chemical route which provides flexibility of processing in a variety of physical forms. Optical absorption spectrum shows significant blue shift from the bulk absorption onset indicating strong quantum confinement. PbS quantumdots of mean size 3.3nm are characterized by X-ray diffraction and transmission electron microscopy. The mechanism of nonlinear absorption giving rise to optical limiting is probed using open z-scan technique with laser pulses of 150 fs pulse duration at 780 nm and the results are presented in the nonresonant femtosecond regime. Irradiance dependence on nonlinear absorption are discussed.

Citation Download Citation

Pushpa Ann Kurian, C. Vijayan, Amit Nag, and Debabrata Goswami "Nonlinear optical properties of free standing films of PbS quantum dots in the nonresonant femtosecond regime", Proc. SPIE 6639, Nanophotonic Materials IV, 66390M (17 September 2007); https://doi.org/10.1117/12.733034

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available