Electro-absorption and Electro-optic Characterization of L-Band InAs& x002F;InP Quantum-dash Waveguide

摘要

Electro-absorption and electro-optic characteristics of InAs& x002F;InP quantum-dash active region-based waveguide, emitting at & x223C;1600 nm is investigated. Two major peaks were observed in the change of absorption spectrum with a maximum value of 7070 cm(& x2212;1) at a bias voltage of -8V with an excellent uniform extinction ratio of & x223C;15 dB across the wavelength range of operation (1460& x2013;1620 nm). The effect of temperature on electro-absorption (EA) measurement suggests a strong influence resulting in merging of two major change of absorption spectrum peaks with higher temperature. Furthermore, electro-optic measurements indicate a change in refractive index and its efficiency values of & x223C;2.9 & x00D7; 10(& x2212;4) and & x223C;0.5 & x00D7; 10(& x2212;4)& x00A0;V-& x2212;1, respectively, hence exhibiting a low chirping factor of 0.9 and 1.5 at bias voltages of & x2212;2& x00A0;V and & x2212;4& x00A0;V, respectively. As a quasi-three-dimensionally confined structure possessing both quantum well- and quantum dot-like features, the quantum dash waveguide showed superior electro-absorption and electro-optic properties compared to quantum dots and close to that of quantum wells, while attaining low chirp and broad wavelength range of operation. This paves a way for potential realization of quantum dash-based EA and electro-optic modulator for future optical access networks, particularly operating in wide C- to L-band region.