The tunable santec laser TSL-550 is integrated into an optical setup to aid us with sensitive reflection and transmission measurements that require fine wavelength increments (approximately 0.01 nm steps).
The user-friendly display panel provides an easy interface to control the wavelength increments, power and other sweep parameters. Additionally, the santec laser also offers a broadband operation, covering the wavelength range from 1560-1680 nm, helping us to acquire the spectral signatures of our photonic materials in a broad spectrum.

Prof. Jennifer Dionne's lab,
Stanford University, USA

Coupling Ratio vs Coupling Length

Measured interference fringes

We wanted to determine the coupling ration of silicon photonic devices' directional couplers with different coupling gaps and lengths. The test setup was simply sweeping the TSL-550 across its scanning range and measuring transmitted power with a photodetector. Measured devices were integrated MZIs with an initial 3dB Y-splitter and the directional coupler as the output splitter. Measured interference fringes gave us an accurate method for characterizing the coupling strength without input/output coupling effects.