A method for hermetically sealing a sensor chip, the method comprising: sealing the sensor chip to an opening of a main package body; inserting a fiber into the main package body through another opening of the main package body; aligning an end of the fiber to the sensor chip, locking the fiber inside the main package body and between the sensor chip opening and the fiber opening, and wherein the fiber is locked inside the main body package at a distance from the end of the fiber that is aligned to the sensor chip; sealing the fiber at the opening of the main package body; applying a fiber jacket to an end of the fiber opposite the end of the fiber that is aligned to the sensor chip, the method being characterised in that the opening of the main package to which the sensor chip is sealed comprises a front snout with an end to which the sensor chip is sealed, in that the opening of the main package through which the fiber is inserted comprises a back snout, in that a portion of the fiber jacket is located inside of the back snout of the main package body; in that an internal cavity of the back snout is sealed, in that a fiber boot is attached to the end of the back snout and to at least a portion of the fiber jacket, in that the fiber is locked in its aligned position inside the main package body on a pedestal located between the front snout and the back snout, in that the fiber end is aligned to the sensor chip via an opening in a top side of the main package body, in that the main package body, the sensor chip, the fiber, the fiber pedestal, the fiber jacket, and the fiber boot are out gassed, and in that lid is sealed to the top side of the main package body. sealing the sensor chip to an opening of a main package body; inserting a fiber into the main package body through another opening of the main package body; aligning an end of the fiber to the sensor chip, locking the fiber inside the main package body and between the sensor chip opening and the fiber opening, and wherein the fiber is locked inside the main body package at a distance from the end of the fiber that is aligned to the sensor chip; sealing the fiber at the opening of the main package body; applying a fiber jacket to an end of the fiber opposite the end of the fiber that is aligned to the sensor chip, the method being characterised in that the opening of the main package to which the sensor chip is sealed comprises a front snout with an end to which the sensor chip is sealed, in that the opening of the main package through which the fiber is inserted comprises a back snout, in that a portion of the fiber jacket is located inside of the back snout of the main package body; in that an internal cavity of the back snout is sealed, in that a fiber boot is attached to the end of the back snout and to at least a portion of the fiber jacket, in that the fiber is locked in its aligned position inside the main package body on a pedestal located between the front snout and the back snout, in that the fiber end is aligned to the sensor chip via an opening in a top side of the main package body, in that the main package body, the sensor chip, the fiber, the fiber pedestal, the fiber jacket, and the fiber boot are out gassed, and in that lid is sealed to the top side of the main package body.