Abstract: A mode-locked solid state laser apparatus including an optical film, a gain medium crystal, a Fabry-Perot element, a first mirror, a second mirror, a third mirror and an output coupler is disclosed. The optical film is configured to receive a pumping light having a first wavelength incident in a first direction. The gain medium crystal receives the pumping light passing the optical film, and generates an initial laser beam having a second wavelength, wherein the initial laser beam forms a first optical path starting at one end thereof from the gain medium crystal. The Fabry-Perot element is disposed on the other end of the first optical path opposite to the one end, and reflects the initial laser beam along a second optical path having one end thereof starting from the Fabry-Perot element.

Abstract: A mode-locked solid state laser apparatus including an optical film, a gain medium crystal, a Fabry-Perot element, a first mirror, a second mirror, a third mirror and an output coupler is disclosed. The optical film is configured to receive a pumping light having a first wavelength incident in a first direction. The gain medium crystal receives the pumping light passing the optical film, and generates an initial laser beam having a second wavelength, wherein the initial laser beam forms a first optical path starting at one end thereof from the gain medium crystal. The Fabry-Perot element is disposed on the other end of the first optical path opposite to the one end, and reflects the initial laser beam along a second optical path having one end thereof starting from the Fabry-Perot element.