Laser wavelength monitoring based on a packaged microbubble resonator

A packaged microbubble resonator with an outer diameter of 210 μm and wall thickness around 3 Μm has been fabricated which can achieve a sensitivity of 71 nm/RIU for refractive index measurement. We further propose it for laser wavelength monitoring with excellent performance verified for both low and high power laser inputs. Combined with the self-referenced differential-mode technique, we can measure the laser wavelength drift of 0.35 pm at low power level and 0.07 pm at high power level, respectively.