Zhiling Luo  
1 School of Physics, Zhejiang University of Technology, Hangzhou 310023, China; [EMAIL_ADDRESS] (Y.L. ); [EMAIL_ADDRESS] (Y.W. ); [EMAIL_ADDRESS] (Z.L. ); [EMAIL_ADDRESS] (X.Y. ); [EMAIL_ADDRESS] (J.Z.) Zhiling Luo  
1 School of Physics, Zhejiang University of Technology, Hangzhou 310023, China; [EMAIL_ADDRESS] (Y.L. ); [EMAIL_ADDRESS] (Y.W. ); [EMAIL_ADDRESS] (Z.L. ); [EMAIL_ADDRESS] (X.Y. ); [EMAIL_ADDRESS] (J.Z.) Zhiling Luo  
1 School of Physics, Zhejiang University of Technology, Hangzhou 310023, China; [EMAIL_ADDRESS] (Y.L. ); [EMAIL_ADDRESS] (Y.W. ); [EMAIL_ADDRESS] (Z.L.L. ); [EMAIL_ADDRESS] (X.Y. ); [EMAIL_ADDRESS] (J.Z.) [PERSON]  
1 School of Physics, Zhejiang University of Technology, Hangzhou 310023, China; [EMAIL_ADDRESS] (Y.L. ); [EMAIL_ADDRESS] (Y.W. ); [EMAIL_ADDRESS] (Z.L. ); [EMAIL_ADDRESS] (X.Y. ); [EMAIL_ADDRESS] (J.Z.) [PERSON]  
1 School of Physics, Zhejiang University of Technology, Hangzhou 310023, China; [EMAIL_ADDRESS] (Y.L. ); [EMAIL_ADDRESS] (Y.W. ); [EMAIL_ADDRESS] (Z.L. ); [EMAIL_ADDRESS] (X.Y. ); [EMAIL_ADDRESS] (J.Z.) [PERSON]  
1 School of Physics, Zhejiang Universityfurther reducing the pulse duration of the X-ray/gamma-ray to sub-femtosecond or even attosecond scales. Compact and bright gamma-ray sources, characterized by ultra-short durations and energies up to several megaelectronvolts (MeVs), demonstrate significant potential across various applications, including ultrafast chemical and biological process diagnostics [14], as well as industrial and defense research [15]. Known as a \"photon collider\", ICS involves a laser photon scattering off relativistic electrons, primarily relying on the double Doppler effect to shift its energy. In the context of an ICS source driven by laser wakefield acceleration, the critical energy of the head-on ICS collision photons can be estimated as follows [12; 16]:  
\[E_{\gamma}\approx 4\gamma_{e}^{2}\hbar\omega_{L}f(a_{0}) \tag{1}\]  
with \(f(a_{0})\approx 1\) for \(a_{0}\ll 1\) and \(f(a_{0})\approx a_{0}\) for \(a_{0}\geq 1\), where \(E_{\gamma}\) is the gamma-ray photon energy, \(\gamma\) is the electron relativistic factor, \(a_{0}\) is the normalized laser vector potential, and \(\hbar\omega_{L}\) is the laser photon energy. If the scattering laser vector potential \(a_{0}\ll 1\), Compton scattering emissions are primarily fundamental. In the case of a head-on collision, the scattered energy observed on-axis roughly scales as \(4\gamma_{e}^{2}\hbar\omega_{L}\). The scattering enters the nonlinear regime at higher laser intensities \(a_{0}\geq 1\), resulting in a radiation spectrum with higher frequencies. This nonlinear effect offers a more efficient option for generating higher-energy X-rays than the LWFA-driven Betatron radiation sources. Two configurations of experimental setup are tested to produce all-optical Compton scattering sources from LWFA electrons [16; 17; 18; 19; 20; 21; 22; 23]. The dual-pulse approach offers flexibility by employing two independent laser pulses, although achieving spatial overlap with micron accuracy and femtosecond synchronization remains highly challenging. Alternatively, a single-laser pulse reflected by a plasma mirror presents a robust and self-synchronized approach [17; 21; 23], albeit accompanied by non-negligible bremsstrahlung radiation [24]. Recent experiments have demonstrated precise-tunable, narrowband, collimated X-ray beams from ICS based on LWFA [25; 26], showing significant potential in various applications. One crucial application of radiation sources based on laser-plasma interaction would be time-resolved pump-probe investigations with sub-femtosecond resolution, as the radiation concentrates within a micrometer-sized volume. Unlike Free Electron Lasers (FELs), the ICS source is typically not regarded as a diffraction-limited source due to its incoherent emission, broad angular distribution, and significant divergence.