System, method, and product for symmetrical filtering in scanning of biological materials

An apparatus comprising:

• an excitation beam provider constructed and arranged to direct an excitation beam to a plurality of locations of a probe array;
• an emission signal detector constructed and arranged to detect an emission signal from at least one location;
• and
• an emission filter comprising a linear-phase filter constructed and arranged to filter the emission signal to provide a filtered emission signal having substantially symmetrical rise and fall edges.

A noise compensation module comprising:

• an excitation signal filter constructed and arranged to filter at least a first and a second excitation signal;
• and
• an emission signal filter constructed and arranged to filter at least a first and a second emission signal;
• wherein the excitation signal filter and the emission signal filter are linear-phase filters, the first excitation signal and corresponding first emission signal are derived from a scan in a first direction, and the second excitation signal and corresponding second emission signal are derived from a scan in a second direction that is opposite to the first direction.

A method comprising the steps of:

• filtering at least a first and a second excitation signal;
• and
• filtering at least a first and a second emission signal;
• wherein the filtering characteristics applied to the first and second excitation signals and to the first and second emission signals are linear-phase, the first excitation signal and corresponding first emission signal are derived from a scan in a first direction, and the second excitation signal and corresponding second emission signal are derived from a scan in a second direction that is opposite to the first direction.