title: Enhanced x-ray emission from nano-particle doped bacteria.
abstract: Recently, it has been greatly appreciated that intense light matter interaction is modified due to the nano- and microstructures in the target by--surface plasmons, laser energy localization scattering etc. Extreme laser intensities produce dense plasmas and collective mechanisms generate energetic electrons, ions and hard x-rays. Recently, it is postulated that the anharmonic electron motion, driven by ultrashort, high-intensity laser pulses, provides a universal mechanism for the laser absorption. Here, we provide the first demonstration of anharmonic-resonance-aided high laser-absorption in a biological system. At intensities of ∼ 10¹⁶⁻¹⁸ W/cm², 40 fs pulses excite a plasma formed with E. coli bacteria. The density-inhomogeneities due to the micro- and nanostructures in the bacterial target increase anharmonic resonance (AHR) heating and result in a 10⁴-fold enhancement in the hard x-ray yield compared to plain solid targets. These observations lead to novel high-energy x-ray sources that have implications to lithography, imaging and medical applications.
authors.forename: M
authors.initials: M
authors.lastname: Krishnamurthy
authors.forename: M
authors.initials: M
authors.lastname: Kundu
authors.forename: Kartik
authors.initials: K
authors.lastname: Bane
authors.forename: Amit D
authors.initials: AD
authors.lastname: Lad
authors.forename: Prashant Kumar
authors.initials: PK
authors.lastname: Singh
authors.forename: Gourab
authors.initials: G
authors.lastname: Chatterjee
authors.forename: G
authors.initials: G
authors.lastname: Ravindra Kumar
authors.forename: Krishanu
authors.initials: K
authors.lastname: Ray