We recently demonstrated nanooptical near-field probing with an 

unprecedented sensitivity  (<1 nm) with the help of ultrafast 

photoelectrons (Rácz et al., Nano Lett. 2017). The task is to extend 

this novel measurement scheme with femtosecond lasers ranging from the 

UV to the mid-infrared spectral domain to enable near-field probing of 

various application-oriented nanostructures. The new experimental 

methods and nanoemitters to be developed will help to advance other 

applications such as the development of ultrafast photocathodes, surface 

enhanced Raman spectroscopy etc. Thus, the applicant will have the 

possibility to gain insight and experience in multiple, forefront 

research fields in ultrafast science.