Wavelength‐Stabilized High‐Pulse‐Power Laser Diodes for Automotive LiDAR

Abstract

For automotive light detection and ranging (LiDAR) systems diode lasers emitting short optical pulses with a good beam quality and a low wavelength shift over a wide operating temperature range is needed. In this paper, theoretical and experimental results of broad area laser diodes specially designed for this application are presented. Optical pulse powers of tens of watts and pulse lengths in the 10 ns-range for wavelengths near 905 nm and environmental temperatures between 15 and 85 C are achieved. Due to the integrated Bragg grating the wavelength shift with temperature is as low as 65 pm K À1 . The contact mesa with a width of 50 μm leads to a lateral M 2 value of about 9. Streak camera measurements of the temporal evolution of the lateral near field intensity reveal that the highest intensity is emitted near the mesa edges. Simulation results of power current characteristics indicate that the power saturation experimentally observed can be attributed to nonlinear effects such as two-photonabsorption and gain compression.

Near‐Infrared Organic Phototransistors with p‐Channel Photosensitive Layers of Conjugated Polymer Composed of bis‐Octyldodecyl‐Diketopyrrolopyrrole and Benzothiadiazole Units

“…For the examination of NIR-absorbing characteristics, the two absorption peaks (λ = 830 and 935 nm) were chosen together with λ = 905 nm that is a representative wavelength for the recent LiDAR technology. [48] As observed from the photoelectron (PE) yield spectrum in Figure 1d, the ionization potential of −5.21 eV was measured for the PODTPPD-BT film under ambient condition, which led to a highest occupied molecular orbital (HOMO) energy of −5.44 eV after calibration. [49,50] Based on the HOMO energy and the optical bandgap energy (E g = 1.21 eV) that could be obtained from the tauc plot of the PODTPP-BT film ( Figure S2, Supporting Information), the lowest unoccupied molecular orbital (LUMO) energy for the PODTPPD-BT film was calculated to be −4.23 eV (see the inset diagram in Figure 1d).…”

“…For the examination of NIR‐absorbing characteristics, the two absorption peaks (λ = 830 and 935 nm) were chosen together with λ = 905 nm that is a representative wavelength for the recent LiDAR technology. [ 48 ]…”

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

“…The light detection and ranging (LiDAR) system, converting distance measurements into signal pulses, has promising applications in driverless vehicles, atmosphere observing, etc. The optical sources of LiDAR can be solid-state lasers [1,2], fiber lasers [3,4] and semiconductor lasers [5][6][7], and are expected to have high peak power [8], high repetition frequency [9], short pulse width [9], and low beam divergence angle [10]. Compared with solid-state lasers and fiber lasers, the semiconductor lasers show a low cost, small volume, easy integration, and the highest conversion efficiency among these laser sources.…”

Novel 900 nm diode lasers with epitaxially stacked multiple active regions and tunnel junctions

“…The cost-effective utilization of a surface grating as demonstrated in ref. [6] is not possible in nanostack lasers because only the laser mode of the uppermost diode would be affected.…”