Absorption of high-intensity, high-contrast femtosecond laser pulses by a dielectric solid. (3rd August 2021)

• Record Type: Journal Article
• Authors: Adak, Amitava; Lad, Amit D; Shaikh, Moniruzzaman; Dey, Indranuj; Sarkar, Deep; Kumar, G Ravindra
• Is Part Of: Plasma physics and controlled fusion. Volume 63:Number 9(2021)
• Publication Date: 2021-08-03
• Subjects: high-intensity laser plasma interactions -- plasma-solid interactions -- laser light absorption in plasmas; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/1361-6587/ac138b
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: Basic understanding of high-intensity femtosecond laser absorption by a solid is crucial for high-energy-density science. This multidimensional problem has many variables like laser parameters, solid target material, and geometry of the excitation. This study is important for a basic understanding of intense laser-matter interaction as well for applications such as 'plasma mirror'. Here, we experimentally observe high-contrast femtosecond laser absorption by an optically polished fused silica target at near-relativistic laser intensities (∼10 18 W cm −2 ). Laser absorption as a function of angle of incidence and incident energy is investigated for both p - and s -polarized pulses in detail, providing a strong indication of the presence of collisionless processes. At an optimum angle of incidence, almost 80% of the p -polarized laser energy gets absorbed by the target. We also observed high reflectivity (∼60%) at lower angle of incidence (30 ∘ ) for both the polarization of laser, indicating this study is fundamentally important for 'plasma mirrors' at near-relativistic intensities.