Semiconductor Optical Amplifiers with Wide Gain Bandwidth and Enhanced Polarization Insensitivity Based on...

Area of Science:

• Optoelectronics
• Materials Science

Background:

• Semiconductor optical amplifiers (SOAs) are crucial for optical communication systems.
• Existing SOAs often face limitations in gain bandwidth and polarization sensitivity.
• Strained quantum well technology offers potential for improved SOA performance.

Purpose of the Study:

• To develop a wide-bandwidth, low-polarization semiconductor optical amplifier (SOA).
• To enhance gain bandwidth and reduce polarization sensitivity using strained quantum wells.
• To improve device performance metrics like gain, noise figure, and transmission loss.

Main Methods:

• Utilized strained quantum wells to enhance material gain for TM modes.
• Implemented a tilted waveguide design to reduce cavity surface reflectance.
• Employed cavity surface optical thin film design to further minimize reflectance.
• Fabricated the device using I-line lithography technology.

Main Results:

• Achieved a small signal gain of 36.4 dB and a 3 dB gain bandwidth of 128 nm at 1550 nm.
• Output power reached 188 mW at a drive current of 1.4 A.
• Demonstrated polarization-dependent gain below 1.4 dB and a noise figure below 5.5 dB.
• Linewidth broadening factor was maintained at 1.032.

Conclusions:

• The developed SOA exhibits wide gain bandwidth, high gain, and low polarization sensitivity.
• The simple fabrication process using I-line lithography ensures low cost and stable performance.
• The SOA is well-suited for wide-bandwidth optical communication applications across S, C, and L bands.