Spectral narrowing in gases using femtosecond laser pulses

Tanvi Karpate; A. K. Dharmadhikari; J. A. Dharmadhikari; D. Mathur

doi:10.1117/12.2268987

16 May 2017 Spectral narrowing in gases using femtosecond laser pulses

Tanvi Karpate, A. K. Dharmadhikari, J. A. Dharmadhikari, D. Mathur

Proceedings Volume 10228, Nonlinear Optics and Applications X; 102280F (2017) https://doi.org/10.1117/12.2268987
Event: SPIE Optics + Optoelectronics, 2017, Prague, Czech Republic

Abstract

Filamentation in gases due to high power femtosecond pulses results from the combined action of the optical Kerr effect (giving rise to self-focusing) and plasma formation (giving rise to defocusing) that confines optical energy in a small region over a distance longer than the Rayleigh range. Since the discovery of N₂ as a potential gain medium, which subsequently led to the formation of nitrogen lasers, it has held a keen interest due to its potential in achieving lasing by remote excitation. Recently, Yamanouchi and coworkers demonstrated lasing action in N₂ in the forward as well the backward directions along the femtosecond pulse propagation. In the present work, we have focused on excitation of N₂⁺ (corresponding to the 391nm spectral feature) and have measured spectral narrowing. We have investigated the influence exerted by the incident pulse power and gas pressure for incident pulses of durations 40 fs and 10 fs in forward and backward detection modes. Spectral narrowing that occurs for N₂ gas at 391 nm shows a dependence on the incident pulse duration. Pressure threshold for different incident powers for lasing has been established. Increase in the signal intensity on varying the incident power is ascribed to amplified spontaneous emission (ASE). White-light-seeded lasing in N₂⁺ is generated by a Ti:sapphire femtosecond laser for different focusing. The lasing lines peak over the trail of the incident broadband spectra.

Conference Presentation

Citation Download Citation

Tanvi Karpate, A. K. Dharmadhikari, J. A. Dharmadhikari, and D. Mathur "Spectral narrowing in gases using femtosecond laser pulses", Proc. SPIE 10228, Nonlinear Optics and Applications X, 102280F (16 May 2017); https://doi.org/10.1117/12.2268987

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