Enhanced performance of 450 nm GaN laser diodes with an optical feedback for high bit-rate visible light communication

Abstract

Enhanced performance of 450 nm GaN laser diodes with an optical feedback for high bit-rate visible light communication. Conference on Lasers and Electro-Optics.

Analysis of optical injection on red and blue laser diodes for high bit-rate visible light communication

“…These trend of optical injection dynamics are similar to that of the injection locked laser diodes reported in the literature [23], and suggests consistency in our measurements and further affirming our attribution of EOI as a signature of EIL. Moreover, Figure 5 also indicates another possible further transition into an unstable region for > 0.7 dB (blue) and > 1.3 dB (red), with inferior performance, as observed in literature [23][24][25]. On the whole, comparing the results of SIL and EOI, we found that the linewidth of blue (red) laser exhibited ~< 80 (~90) pm value under selfinjection and ~78(~100) pm value under external-injection, and at a fixed IR of -0.7 dB and -1.25 dB, respectively.…”

“…Besides, a clear eye diagram at 2.0 Gb/s of the SIL and the FR laser diodes, shown in the insets of Figures 8 (a) and (b), displays an error-free transmission. The authors' strongly believes that the limitation of APD bandwidth possibly have restricted observation of further improvement from the SIL system and attributed this slight improvement in part to a slight increase in the integrated power of the system, and partly to reduced system noise, under SIL, which has been observed previously [24]. A clear distinction in the transmission performance should be possible if phase modulation schemes were to be employed, as it is well known that injection locking substantially reduces the intensity as well as phase noise of the SIL laser system.…”

“…1 (a) shows the experimental setup of the self-injection locking scheme in the blue and red laser diode. In this experiment, commercial blue (Osram PL450B) and red (Sanyo DL6148-030) laser diodes have been used as the optical sources on a standard 1GHz bandwidth laser diode mount (Thorlabs LDM9T) [24]. A silver-coated mirror (Thorlabs PF10-03-P01) with 97.5% reflectivity at 19 cm apart, forming an external cavity, is used to enable optical feedback to the source.…”

Investigation of Self-Injection Locked Visible Laser Diodes for High Bit-Rate Visible Light Communication

“…In summary, a maximum bandwidth enhancement of ∼880 MHz (1.53-2.41 GHz) for green, ∼540 MHz (1.72-2.26 GHz) for the blue and ∼320 MHz (1.92-2.24 GHz) for the red laser diodes are achieved via self-injection locking technique. It is worth mentioning at this instance that all these lasers exhibited significant performance improvement compared to our first and initial results on spectral linewidth (∼1.3 times) and modulation bandwidth (∼2 times) improvement, which were reported on an unoptimized setup [16], [17].…”

“…Very recently, owing to the merits offered by SIL viz. energy efficiency, compact scheme, etc., our group successfully demonstrated SIL on 524 nm green [16] and 450 nm blue InGaN/GaN diode lasers [17]. Besides, [18] utilized SIL to demonstrate a single longitudinal mode operation at 446.5 nm blue laser diode with magnesium fluoride (MgF 2 ) whispering gallery mode (WGM) resonator.…”