Abstract

Active optoelectronic devices made from semiconductor multiple quantum wells (MQWs) have been attracting much attention recently because of the large optoelectronic properties observed in these materials. For example, an electroabsorption effect in GaAs/AlGaAs MQWs^[1] has been observed with a change in optical absorption coefficient as large as Δα = 15,000 cm⁻¹. Recently, much progress has been made in applying this technology to long-wavelength materials. For example, a GaSb/AlGaSb^[2] waveguide modulator was reported with a Δα = 5500 cm⁻¹ at a wavelength of λ = 1.55 μm. A waveguide device made from GaInAs/InP MQWs^[3] that had Δα = 400 cm⁻¹ at λ = 1.55 μm, and produced an on/off ratio R = 8:1 has been reported. Also, a waveguide device with an insertion loss as low as 2.9 dB in InGaAs/InP MQWs^[4] at λ = 1.67 μm has been reported, but the 47:1 on/off ratio was achieved in a waveguide that was fairly long (L = 375 μm), and the Δα was only 640 cm⁻¹. For applications in high-performance lightwave systems, shorter devices with larger Δα are necessary so that higher speeds can be achieved.

© 1988 Optical Society of America