Zhang Can

Selected area growth integrated wavelength converter based on PD-EAM optical logic gate

A selected area growth wavelength converter based on a PD-EAM optical logic gate for WDM application is presented, integrating an EML transmitter and a SOA-PD receiver. The design, fabrication, and DC characters were analyzed. A 2 Gb/s NRZ signal based on the C-band wavelength converted to 1555 nm with the highest extinction ratio of 7 dB was achieved and wavelength converted eye diagrams with eyes opened were presented.

A 1.55-μm laser array monolithically integrated with an MMI combiner

The monolithic integration of four 1.55-μm range InGaAsP/InP distributed feedback lasers with a 4 × 1 multimode-interference (MMI) optical combiner using the varied width ridge method is proposed and demonstrated. The average output power is 1.5 mW when the current of LD is 100 mA and the threshold current is 30–35 mA at 25 °C. The lasing wavelength is 1.55-μm range and 40 dB sidemode suppression ratio is obtained. The four channels can operate separately or simultaneously.

Temperature Characteristics of Monolithically Integrated Wavelength-Selectable Light Sources

The temperature characteristics of monolithically integrated wavelength-selectable light sources are experimentally investigated. The wavelength-selectable light sources consist of four distributed feedback (DFB) lasers, a multimode interferometer coupler, and a semiconductor optical amplifier. The oscillating wavelength of the DFB laser could be modulated by adjusting the device operating temperature. A wavelength range covering over 8.0nm is obtained with stable single-mode operation by selecting the appropriate laser and chip temperature. The thermal crosstalk caused by the lateral heat spreading between lasers operating simultaneously is evaluated by oscillating-wavelength shift. The thermal crosstalk approximately decreases exponentially as the increasing distance between lasers.

Design and Fabrication of a 1-by-4 Multimode Interference Couplers Based on InP

Multiple wavelength DFB laser array and multimode interference coupler integrated light source device has important application prospect in the dense wavelength division multiplexing system.A strongly guided InP/InGaAsP multimode interference coupler is designed and simulated by using 3D FD-BPM method in order to research the optical coupler used in the broadband available multiple wavelength integrated light source.Tapered input/output waveguides are used to reduce the insertion loss of the multimode interference coupler and to improve the uniformity of the output ports.Combined with the metal organic chemical vapor deposition(MOCVD) epitaxial growth apparatus and according to the simulation results,a 1-by-4 multimode interference coupler is fabricated by using reactive ion etching process.The insertion loss and the uniformity of the device is measured by automatic alignment waveguide coupling test system.The test result shows that the device has 40nm available bandwidth and 2.6dB pass band flatness around 1550nm.Furthermore,the insertion loss is no higher than 10dB at the designed wavelength 1550nm.