Integrated optical Ti:Er:LiNbO3 distributed Bragg reflector laser with a fixed photorefractive grating

Area of Science:

• Photonics and Laser Technology
• Materials Science
• Integrated Optics

Background:

• Distributed Bragg reflector (DBR) lasers are crucial for optical communication.
• Lithium niobate (LiNbO3) is a versatile material for integrated optics due to its nonlinear and photorefractive properties.
• Photorefractive gratings offer a method for creating tunable and fixed optical elements.

Purpose of the Study:

• To demonstrate the first integrated optical DBR laser with a fixed photorefractive grating in LiNbO3.
• To characterize the fabrication process and laser performance of the device.
• To explore the potential of LiNbO3 for advanced integrated photonic devices.

Main Methods:

• Fabrication of a LiNbO3-based optical device incorporating a fixed photorefractive grating.
• Pumping the device using a fiber-pigtailed laser diode at approximately 1480 nm.
• Employing a double-pass configuration through the Bragg grating for backward emission.
• Characterizing laser emission wavelength, threshold power, and output power in continuous-wave (cw) operation.

Main Results:

• Successful demonstration of an integrated optical DBR laser with a fixed photorefractive grating in LiNbO3.
• Observed laser emission in the backward direction at a wavelength of 1531.7 nm.
• Achieved a laser threshold of 40 mW.
• Obtained as much as 5 mW of output power at 110 mW of launched pump power.

Conclusions:

• The integration of a fixed photorefractive grating in LiNbO3 enables the development of novel DBR lasers.
• The demonstrated device shows promising performance for integrated photonic applications.
• This work paves the way for further advancements in LiNbO3-based photonic integrated circuits.