Abstract
Slope efficiency (SE) is an important performance metric for lasers. In conventional semiconductor lasers, SE can be optimized by careful designs of the facet (or the modulation for DFB lasers) dimension and surface. However, photonic wire lasers intrinsically suffer low SE due to their deep sub-wavelength emitting facets. Inspired by microwave engineering techniques, we show a novel method to extract power from wire lasers using monolithically integrated antennas. These integrated antennas significantly increase the effective radiation area, and consequently enhance the power extraction efficiency. When applied to wire lasers at THz frequency, we achieved the highest single-side slope efficiency (~450 mW/A) in pulsed mode for DFB lasers at 4 THz and a ~4x increase in output power at 3 THz compared with a similar structure without antennas. This work demonstrates the versatility of incorporating microwave engineering techniques into laser designs, enabling significant performance enhancements.
Highlights
Photonic wire lasers [1,2] and nano lasers [3,4] are new genres of laser structures that are of interests in applications such as ultrafast optical modulation [5] and frequency tuning [6]
We demonstrate a new type of laser structure with enhanced power extraction efficiency by coupling integrated antennas to the laser waveguide to form a distributed feedback structure
The approach described in this letter is inspired by microwave engineering designs, where sub-wavelength slot antennas [9] are widely used in microstrip transmission line system
Summary
Photonic wire lasers [1,2] and nano lasers [3,4] are new genres of laser structures that are of interests in applications such as ultrafast optical modulation [5] and frequency tuning [6]. These waveguides can be viewed as microwave transmission lines operating at a much higher frequency Following this analogy, we demonstrate a new type of laser structure with enhanced power extraction efficiency by coupling integrated antennas to the laser waveguide to form a distributed feedback structure. The approach described in this letter is inspired by microwave engineering designs, where sub-wavelength slot antennas [9] are widely used in microstrip transmission line system. For those antennas, the microstrip waveguide consists of dielectric material sandwiched by a narrow metal strip and an infinite metal ground plane, and the antennas are formed by removing parts of the metal on the ground plane [see Fig. 1(a), left]. The shape and the position of this microstrip slot antenna can be adjusted to maximize the power extraction efficiency, which is referred to as “impedance matching” in microwave engineering
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
