Chirp-based direct phase modulation of VCSELs for cost-effective transceivers

Area of Science:

• Optoelectronics
• Optical Communications
• Laser Technology

Background:

• Vertical cavity surface emitting lasers (VCSELs) are crucial components in modern optical communication systems.
• Direct modulation of VCSELs is desirable for cost-effective transmitter designs.
• Chirp characteristics of VCSELs can be leveraged for advanced modulation schemes.

Purpose of the Study:

• To propose and characterize a 2.5 Gb/s differential binary phase-shift keying (DPSK) transmitter.
• To utilize the intrinsic chirp of a VCSEL for direct phase modulation.
• To evaluate the performance of the proposed transmitter with a heterodyne receiver.

Main Methods:

• Direct phase modulation of a 1539.84 nm wavelength VCSEL.
• Static and dynamic characterization of the VCSEL.
• System-level testing with a single photodiode heterodyne receiver.

Main Results:

• Successful implementation of a 2.5 Gb/s DPSK transmitter.
• Demonstration of direct phase modulation using VCSEL chirp.
• Achieved receiver sensitivity of -39.5 dBm.

Conclusions:

• The proposed VCSEL-based DPSK transmitter is a viable and cost-effective solution.
• Direct phase modulation using VCSEL chirp enables efficient data transmission.
• The technology is suitable for deployment in future access networks.