Light source for variable path length systems

A wavelength selection mechanism for use in sample analysis, the wavelength selection mechanism comprising:

• a spectrometer for receiving light from a light source and for outputting light at a plurality of different wavelengths;
• an optical receiving component (ORC) for receiving the light outputted by the spectrometer;
• and
• an actuator coupled to one of the ORC and the spectrometer, the actuator configured to selectively adjust a relative position along a first axis between the ORC and the spectrometer such that the ORC receives a selected one of the plurality of light outputs, the selected one of the plurality of light outputs having a wavelength for determining a targeted compound in the sample, and wherein the actuator is configured to adjust a relative position along a second axis perpendicular to the first axis to position the ORC with respect to the selected one of the plurality of light outputs at a location within the selected one of the plurality of light outputs at which a desired light intensity exists.

A method for determining a characteristic of a sample, comprising:

• directing a light into an input of a spectrometer;
• at the spectrometer, splitting the light into a plurality of light outputs each having a different wavelength;
• projecting the plurality of light outputs onto an active wavelength selection module (AWSM);
• moving at least one of the spectrometer and an optical receiving component (ORC) of the AWSM with respect to each other along a scanning direction such that the ORC receives light from a selected one of the plurality of light outputs;
• moving at least one of the spectrometer and the ORC of the AWSM with respect to each other in a direction perpendicular to the scanning direction to position the ORC with respect to the selected one of the plurality of light outputs at a location within the selected one of the plurality of light outputs at which a desired light intensity exists;
• directing the received light to a sample;
• collecting a quantity of the received light that passes through the sample;
• directing the collected quantity of the received light to an analysis module;
• and
• at the analysis module, correlating the collected light with a characteristic of the sample.

A method for calibrating a selection mechanism for use in sample analysis, comprising:

• at a spectrometer, splitting input light into a plurality of light outputs each having a different wavelength;
• projecting the plurality of light outputs onto an optical receiving component (ORC) of an active wavelength selection module (AWSM);
• moving at least one of the spectrometer and the ORC along a scanning direction by a predetermined amount such that the ORC receives light from a selected one of the plurality of light outputs;
• moving at least one of the spectrometer and the ORC perpendicular to the scanning direction such that the ORC is positioned with respect to the selected one of the plurality of light outputs at a location within the selected one of the plurality of light outputs at which a desired light intensity exists;
• directing the received light to a calibration module;
• at the calibration module, correlating a position of the ORC with a wavelength of the light received at the position;
• in a memory device, saving the position of the ORC and the wavelength of the light received at the position;
• and
• repeating the projecting, moving at least one of the spectrometer and the ORC along a scanning direction, moving at least one of the spectrometer and the ORC perpendicular to the scanning direction, directing, correlating, and saving steps to obtain a calibration matrix that correlates a plurality of positions of the ORC with a plurality of wavelengths of light received at each of the plurality of positions.