Fig. 4: Fundamental transverse modes behaviors.

a Calculated L‐I curves of LP₀₁, LP₁₁, and LP₂₁ transverse modes. b Calculated radial intensity distributions of the LP₀₁, LP₁₁, and LP₂₁ transverse modes at injection currents of 1 mA (dashed curves) and 5 mA (solid curves). The oxide aperture boundary is marked by the vertical dashed line. The inset presents corresponding 2D mode profiles, illustrating the distinct field confinement characteristics of each mode. c Emission spectra at different injection currents (1–6 mA) at room temperature (25 °C). The inset displays the peak wavelength shift (Δλ/ΔI), showing a linear tuning coefficient of 0.53 nm/mA. d Divergence angle of the output beam measured in two orthogonal directions. The dashed lines represent the D₅₀ divergence profile. e Far-field intensity profiles at 85 °C under various drive currents (2–7 mA), demonstrating consistently low beam divergence below ~7.0°