Optical apparatus

An optical apparatus for use with an analytical apparatus arranged to project an analysis beam along an analytical axis towards a sample within a sample chamber, the optical apparatus comprising:

• a collection optic mounted on an arm, the arm being insertable or inserted into the sample chamber through a port in the sample chamber to locate the collection optic for directing light scattered or generated from a point on the sample out of the sample chamber;
• a drive mechanism comprising at least one translation stage for moving the collection optic within the sample chamber
• a pressure sensor for measuring pressure in the sample chamber;
• and
• a light source control system configured to cause at least one light source to be switched off if the measured pressure in the sample chamber deviates from a pre-set operating pressure.

A method of collecting light scattered or generated from a sample in a sample chamber of an analytical apparatus, the analytical apparatus arranged to project an analysis beam along an analytical axis towards the sample within a vacuum in the sample chamber, the method comprising:

• providing (i) a collection optic for directing light scattered or generated from a point on the sample out of the sample chamber and (ii) a drive mechanism comprising:
• translation stages for moving the collection optic within the sample chamber in at least two transverse directions;
• one or more actuators external to the sample chamber for moving the translation stages;
• and
• encoders for measuring a position of each translation stage;
• and
• spectroscopically mapping the sample by operating the one or more actuators to move the collection optic within the sample chamber such that the collection optic directs light from different points on the sample for each of a plurality of positions of the collection optic in the sample chamber, wherein the movement of the translation stages is controlled based on feedback from the encoders.