Single-lens pathway for emission and excitation using a mirror and beam splitter in a customizable optical head

A small form factor optical head defining a single light pathway, comprising:

• a housing;
• a lens;
• a light source positioned in the housing;
• a photodiode positioned in the housing;
• a lens block positioned in the housing;
• a mirror positioned in the housing;
• first and second filters positioned in the housing;
• wherein the lens block is configured to receive the light source, the photodiode, the first and second filters, the mirror and the beamsplitter in a first side thereof and the lens is positioned at a second side thereof,
• wherein the lens is configured to focus the excitation light and to allow emission light to pass through the lens,
• wherein the beam splitter directs the excitation light toward the lens, and directs emission light to a detector.

A method for optical analysis, comprising:

• providing an optical head having a housing, a lens positioned on or in the housing, a light source positioned in the housing, the light source configured to emit an excitation light, a mirror positioned in the housing to reflect the excitation light to the lens and to receive emission light back through the lens, a beamsplitter positioned in the housing to direct the excitation light to the lens and to direct the emission light, and a detector positioned to receive emission light after passing back through the lens and the beam splitter, wherein the lens, the mirror, and the beam splitter define a single light pathway for the excitation light and emission light;
• emitting a light beam from the light source;
• receiving an emission beam;
• and
• analyzing the emission beam.