Tunable ring laser with internal injection seeding and an optically-driven photonic crystal reflector

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Conventional tunable lasers often face limitations in tuning range and efficiency.
• Developing broadly tunable and efficient laser sources is crucial for various spectroscopic applications.

Purpose of the Study:

• To demonstrate a novel hybrid laser architecture for continuous wavelength tuning.
• To investigate the performance of an optically-driven photonic crystal reflector in a laser cavity.

Main Methods:

• A hybrid ring/external cavity laser was designed, incorporating a photonic crystal with an azobenzene overlayer as a tunable grating reflector.
• The laser system utilized a 532 nm light source to optically drive the reflector and an injection-seeded semiconductor amplifier for gain.
• Frequency selectivity was achieved through the photonic crystal's passband and line narrowing in the high-gain amplifier.

Main Results:

• Continuous tuning over a 1.6 THz region (842.5-848.6 nm) was successfully achieved.
• The optically-driven photonic crystal reflector exhibited a peak reflectivity of ~80% and tunable response.
• Sub-0.1 nm linewidths and over 97% amplifier extraction efficiencies were observed.

Conclusions:

• The hybrid laser design offers a new approach for achieving broad and continuous wavelength tuning.
• The optically-driven photonic crystal reflector provides an effective mechanism for laser wavelength control.
• This laser system demonstrates high performance in terms of tuning range, linewidth, and efficiency.