This patent application pertains to the optical laser microscopy field and proposes a simplified yet specific optical laser coupling method. The proposed method allows for a sensible reduction in size and complexity of laser based microscopes and related applications, especially in the area of nano particles detection and optical biosensing. Particularly the optical laser coupling proposed method can detect optical signals generated from sub-diffractive nanoparticles located in liquid solution on a standard glass coverslip. Thanks to the small size of the required components and to the usage of standard air-lens objective, without the presence of oil or special prism, this method can be easily embedded into a small, lightweight and portable device, which can properly operate even in absence of gravity.
