Micro ring grating spectrometer with adjustable aperture

A spectrometer comprising:

• a micro-ring grating device having a plurality of coaxially-aligned ring gratings, wherein the ring gratings are configured for directing a predetermined frequency band of incident light onto a target focal point;
• an adjustable aperture device defining a circular aperture circumscribing the target focal point;
• a detection device adapted for detecting the intensity of a selected portion of the predetermined frequency band, and for converting the detected intensity into a corresponding proportional electrical signal;
• a linear actuator connected to the aperture device, wherein the linear actuator is configured for selectively changing the distance between the aperture device and the grating device to thereby modify the focal length of the spectrometer;
• and
• a Micro-Electro-Mechanical System (MEMS) device connected to the aperture device and configured for changing the diameter of the circular aperture.

A method of detecting the intensity of a selected frequency band of incident light, the method comprising:

• directing the incident light onto a plurality of coaxially-aligned ring gratings of a micro-ring grating device;
• diffracting a predetermined frequency band of the incident light onto a target focal point using the ring gratings;
• using at least one actuator to selectively adjust an adjustable aperture device to thereby pass a selected portion of the frequency band to a detection device;
• detecting the intensity of the selected portion using the detection device.