Optical component for generating a periodic light pattern

A method for illuminating a sample region of an optical component, the method comprising:

• providing an optical component comprising a first waveguide, a further waveguide, and an optical splitter;
• receiving input light at the optical splitter;
• receiving first input light in the first waveguide from a first output of the optical splitter;
• using total internal reflection within the first waveguide to direct the first input light into the sample region along a first path in a first direction;
• directing, from a second output of the optical splitter, second input light into the sample region along a second path in a second direction, wherein the second direction is different from the first direction;
• receiving third input light in the further waveguide;
• using total internal reflection within the further waveguide to direct the third input light into the sample region along a third path in a third direction, wherein the third direction is different from the first and the second directions, and the first, second and third directions are coplanar;
• and
• interfering the first input light and the second input light, or the first, second and the third input light, together to form a periodic light pattern in the sample region.

A system for imaging a sample using structured illumination microscopy, the system comprising:

• a light-injecting apparatus;
• an optical component comprising a first waveguide, a further waveguide and an optical splitter, the optical splitter having (i) an input for receiving input light, (ii) a first output, and (iii) a second output, wherein:
• the first output of the optical splitter is optically coupled to the first waveguide so as to direct first input light into the waveguide;
• the first waveguide is arranged to use total internal reflection to direct the first input light into the sample region along a first path in a first direction;
• the second output of the optical splitter is optically coupled to the sample region so as to direct second input light into the sample region along a second path in a second direction;
• the further waveguide is arranged to receive third input light and to use total internal reflection to direct the third input into the sample region along a third path in a third direction;
• the second direction is different from the first direction so that, in use, the first input light interferes with the second input light to form a periodic light pattern in the sample region;
• the third direction is different from the first direction and from the second direction;
• and
• the first, second and third directions are coplanar;
• an objective lens arranged to collect light emanating from the sample region;
• and
• an imaging unit arranged to perform structured illumination microscopy with the collected light.