A modal interferometer is experimentally demonstrated based on tapering a single-mode-multimode-singlemode (SMS) fiber structure heated by hydrogen flame.The interference fringe begins to form when tapering length is 19.8 mm,and becomes regular and clear when the tapering length is longer and the tapered waist diameter is smaller.Annealing process is undertaken to achieve a high extension ratio of approximately 17 dB with free spectral range of 1.5 nm when the tapering length is 33 mm and the tapered waist diameter is approximately 5μm.The temperature and axial strain dependences of the tapered SMS structure are characterized,and the measured temperature and strain coefficients are +7 pm/℃and -9.536 pm/με, respectively.
We demonstrate binary phase shift keying(BPSK) modulation using a silicon Mach–Zehnder modulator with aπ-phase-shift voltage(Vπ) of-4.5 V.The single-drive push–pull traveling wave electrode has been optimized using numerical simulations with a 3 dB electro-optic bandwidth of 35 GHz.The 32 Gb/s BPSK constellation diagram is measured with an error vector magnitude of 18.9%.
We explore all-optical wavelength conversion in a microdisk resonator integrated with interleaved p-n junctions.Numerical simulation based on temporal coupled mode theory is performed to study the free-carrier dynamics inside the cavity.It reveals that the detuning of pump and probe frequencies and the carrier lifetime have a significant effect on the device performance.Experimental result confirms that the conversion speed can be considerably improved by applying a reverse bias on the p-n junctions.Wavelength conversion at 10 Gb/s data rate is achieved with a pump power of 5.41 dBm and a bias voltage of-6 V.
