Mode stability in photonic-crystal surface-emitting lasers with large κ1DL

Abstract

We study mode stability in photonic-crystal surface-emitting lasers (PCSELs) with large coupling-coefficient-length product κ1DL(>6). We observe that mode competition occurs at high current levels above threshold. Our combined experimental and theoretical study provides the first evidence of the mode competition originating from the high-order band-edge modes. The decreased threshold margin between these competing high-order modes and the main lasing mode with increasing cavity length as well as the spatial hole burning effect may deteriorate the single-mode stability. Our finding is essential for designing single-mode high-power PCSELs for which the strategy to suppress the high-order modes must be considered.

Photonic Crystal Surface Emitting Laser Operating in Pulse-Periodic Regime with Ultralow Divergence Angle

“…The short pulse width is important for obtaining enough detecting precision and ensuring eye safety, especially for wavelengths less than 1.5 µm [9]. However, until now, it has lacked detailed investigation in this regard, although their other properties such as polarization and beam pattern have been discussed previously [22][23][24][25].…”

Analytical coupled-wave model for photonic crystal surface-emitting quantum cascade lasers

“…Figure 3 profiles of these modes are shown in Fig. 3(b), all of which have only one antinode throughout the whole cavity area [23]. Here, the mode intensity profile is defined as: I(x, y) = |R x | 2 + |R y | 2 + |S x | 2 + |S y | 2 [22].…”

“…In recent years, we have developed a 3D analytical coupled-wave theory (CWT) framework to investigate the physics of photonic crystal structures [17,18,19,20,21,22,23,24,25], which provides reliable 3D modeling of photonic crystal surface-emitting laser (PCSEL) struc-tures [11] and bound states in continuum (BIC) [26,27,28]. Moreover, this model has been extended from TE mode to study TM-mode coupling behavior within PhC structures [29,30].…”

Electrically Pumped Epitaxially Regrown GaSb‐Based Type‐I Quantum‐Well Surface‐Emitting Lasers with Buried High‐Index‐Contrast Photonic Crystal Layer

“…It is well known that excitation of the higher‐order modes of the PCSEL device can degrade its brightness. [ 23 ] However, it is not expected to produce a current independent far‐field pattern with so separated narrow beams. The observed far‐field structure is somewhat reminiscent of what was reported for PCSELs specially designed to demonstrate the lasing band edge at non‐zero in‐plane photon wavevector.…”