Abstract: An apparatus for imaging or fabrication using charged particles, the apparatus including: a charged particle source configured to generate a charged particle beam of ions or electrons; a sample holder mounted relative to the charged particle source to hold a sample in the charged particle beam for the imaging or fabrication; and an optical source system configured to generate an optical beam, wherein the optical source system is mounted relative to the sample holder to direct the optical beam onto the sample to modify an electric charge of the sample during the imaging or fabrication to improve spatial resolution of the imaging or fabrication.