Electroabsorption modulators operating at 1.3 μm on GaAs substrates

✍ Scribed by S. M. Lord; B. Pezeshki; J. S. Harris

• Book ID: 104770847
• Publisher: Springer
• Year: 1993
• Tongue: English
• Weight: 675 KB
• Volume: 25
• Category: Article
• ISSN: 0306-8919
• DOI: 10.1007/bf00430337

✦ Synopsis

This paper describes the growth and device performance of electroabsorption modulators on GaAs substrates operating near 1.3#m, the dispersion minimum for silica fibres. The key to the successful molecular beam epitaxial (MBE) growth of these devices was the incorporation of a linearly-graded buffer layer beneath the InGaAs/ AIGaAs multi-quantum-well active layer. Both transmission and reflection modulators are produced. For transmission devices, larger modulation is achieved when the buffer is graded more slowly. The maximum modulation reported was 22% for AT/To corresponding to a 0.86dB contrast ratio with an insertion loss of roughly 5dB at 1.34#m. Antireflection coating a transmission modulator yields a reasonable reflection modulator. However, improved performance is reported for a reflection modulator using a novel technique of integrating the bottom quarter-wave mirror into a buffer with linearly-graded In composition. At 1.33 #m, a normally-off reflection modulator with an integrated mirror exhibited a AR/R o of 73%, a contrast ratio of 2.38 dB, and an insertion loss of 4dB.