Spectroscopic analysis apparatus and method with excitation system and focus monitoring system

An analysis method, in particular a spectroscopic analysis method, for analyzing an object comprising the steps of:

• emitting an excitation beam from a first source to excite a target region;
• emitting a monitoring beam from a second different source to image the target region by an imaging system;
• detecting scattered radiation from the target region generated by the excitation beam,
• focusing the imaging system on at least two substantially parallel imaging planes within the object at a predetermined distance;
• focusing the excitation system and the detection system on a detection plane within the object substantially parallel and in-between the imaging planes at predetermined distances;
• determining an amount of defocus of the imaging system from the detection plane for the at least two imaging planes;
• and
• controlling the focusing to commonly change the focusing of the imaging system, the excitation system and the detection system based on the determined amount of defocus and the predetermined distances between the imaging planes and the detection plane such that a difference between the determined amount of defocus for the at least two imaging planes equals a predetermined amount.

An optical tracking system for continuously tracking a point of a moving object, comprising:

• a target system comprising a first source emitting a light beam to be focused on the tracked point;
• a monitoring system comprising a second different source for emitting a monitoring beam and an imaging system to image the target region;
• focusing means for focusing the imaging system on at least two substantially parallel imaging planes within the object at a predetermined distance and for focusing the target system on a detection plane within the object substantially parallel and in-between the imaging planes at predetermined distances;
• defocus detection means for determining an amount of defocus of the imaging system from the detection plane for the at least two imaging planes;
• and
• auto-focusing means fox controlling the focusing means to commonly change the focusing of the imaging system and the target system based on the determined amount of defocus and the predetermined distances between the imaging planes and the detection plane such that a difference between the determined amount of defocus for the at least two imaging planes equals a predetermined amount.