There is described an optical pressure sensor comprising a sensor housing and an optical pressure cell mounted within the sensor housing and dividing the sensor housing into a first fluid space and a second fluid space. The optical pressure cell comprises a front side exposed to a pressure in the first fluid space and a back side exposed to a pressure in the second fluid space. The optical pressure sensor further comprises a fluid communication arrangement allowing pressure equalization between the pressure in the first fluid space on the front side and the pressure in the second fluid space on the back side of the optical pressure cell.