| 摘要 |
<p>An apparatus for performing spectroscopy incorporates, between an EM source and a detector, an optical filter comprising a pair of mirrors opposed along the optical axis and shaped to provide an optical cavity with stable resonance and having a cavity length of at most 50µm and a mode at a wavelength within said band of wavelengths for bandpass filtering EM radiation passing therethrough. The actuator system is arranged to move the mirrors relative to each other along the length of the optical cavity for tuning the wavelength of said mode.</p> |
