Tunable coupled-cavity waveguide laser at room temperature in Nd-diffused Ti:LiNbO(3).

Area of Science:

• Photonics
• Materials Science
• Laser Technology

Background:

• Neodymium-doped titanium-indiffused lithium niobate (Nd:Ti:LiNbO3) is a key material for integrated optical devices.
• Channel waveguides offer miniaturization and enhanced light-matter interaction for laser applications.

Purpose of the Study:

• To develop and characterize a Y-junction channel waveguide laser operating at room temperature.
• To investigate the performance of such a laser with different feedback mechanisms.
• To demonstrate wavelength tuning capabilities integrated with phase modulation.

Main Methods:

• Fabrication of a Y-junction channel waveguide in Nd:Ti:LiNbO3.
• Optical pumping using a continuous-wave Ti:Al2O3 laser at 816 nm.
• Characterization of lasing threshold and slope efficiency with and without high-reflectivity mirrors.
• Demonstration of wavelength tuning using an integrated phase modulator.

Main Results:

• Achieved continuous-wave (cw) lasing at room temperature.
• Obtained a cw lasing threshold of approximately 39 mW pump power with polished end faces.
• Reduced the lasing threshold to approximately 4 mW using 95% reflectivity mirrors.
• Demonstrated a slope efficiency of approximately 35% without mirrors and 2.6% with mirrors.
• Tuned the lasing signal over 2.3 nm around 1092.7 nm.

Conclusions:

• The Y-junction channel waveguide laser in Nd:Ti:LiNbO3 is a viable room-temperature device.
• Integrated feedback mirrors significantly reduce the lasing threshold.
• The device exhibits tunable lasing and can be integrated with phase modulators for advanced photonic functionalities.