Ted in this study are available on affordable request from the corresponding author.Photonics 2021, 8,eight ofAcknowledgments: The support of Fonds europ n de d eloppement r ional (FEDER) and also the Walloon region below the Operational Program “Wallonia-2020.EU” (project CLEARPOWER) is gratefully acknowledged. Conflicts of Interest: The authors declare no conflict of interest.
hvphotonicsArticleSimultaneous Enhancement of Contrast and Power of Femtosecond Laser Pulses by nonlinear InterferometerYasser Nada 1, and Efim Khazanov1Physics Department, Faculty of Science, Menofia University, Shibin El-Kom, Menofia 32511, Egypt Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod 603950, Anle138b Purity Russia; [email protected] Correspondence: [email protected]: We showed that the nonlinear Mach ehnder interferometer could possibly be utilized not only for enhancing Brofaromine InhibitorBrofaromine Purity & Documentation temporal contrast, as proposed earlier, but in addition for escalating pulse power on account of effective pulse compression. The interferometer introduces into the output pulse a nonlinear phase equal to /2. This makes it possible for increasing laser energy by a issue of 1.5 only by means of a chirped mirror. Use of an additional nonlinear plate leads to a multi-fold power improve retaining the contrast enhancement. Search phrases: nonlinear Mach ehnder interferometer; post compression; femtosecond laser pulse contrast; self phase modulation1. Introduction High temporal contrast has a crucial part in experiments on studying the behavior of matter in intense light fields. Temporal contrast is definitely the ratio of your intensity at the peak on the pulse for the intensity on its pedestal. The pedestal seems, as a rule, due to amplified spontaneous emission in laser amplifiers of CPA lasers (chirped pulse amplification) [1], or as a consequence of amplified parametric emission in OPCPA lasers (optical parametric chirped pulse amplification) [2]. Essentially the most well known methods for contrast enhancement are plasma mirrors [3], harmonic generation [4], and cross-polarized wave (XPW) generation [5]. XPW is primarily based on cubic nonlinearity. Not too long ago, quite a few new tips have been proposed for contrast enhancement, by implies of a nonlinear phase induced by cubic nonlinearity: spectral filtering [6,7], spatial filtering [8], a nonlinear polarization interferometer [9], also as a nonlinear Mach ehnder interferometer with symmetric arms [10]. Within the latter case, the phase difference with out non-linearity L equals , and the radiation from the pedestal will not pass to the dark port (see Figure 1a). On the contrary, the primary pulse acquires a nonlinear phase B (B-integral) in 1 channel, as well as a zero nonlinear phase in an additional one particular. If B is nonzero, then the dark port does not come to be fully dark. If B = , then the dark port becomes a light port, and also the significant a part of the primary pulse comes via this port. Consequently, the contrast might be infinitely high if = . In practice, the contrast enhancement is determined by the inaccuracy of meeting the condition = . Because of self-phase modulation (SPM) within a nonlinear medium, and subsequent reflection from the chirped mirror (CM), the pulse may very well be compressed, and therefore the peak power increases. The method is known as TFC (thin film compression) [11], CafCA (compression after compressor approach) [12], or post-compression [13]. For pulses with power of tens of Joules [146], the numerous compression of femtosecond laser pulses was demonstrated with virtually no energy loss; for additional information, see the review [17]. In th.
