Blue Laser Diode System With an Enhanced Wavelength Tuning Range

Abstract

A prism-based self-injection locked seamlessly tunable blue InGaN/GaN laser diode composite cavity system is presented. A rigorous analysis of this external cavity diode laser (ECDL) system is performed at two different optical feedback powers. At 130 mA low injection, the high reflection system (HRS) exhibits a record wideband tuning span of ∼12.11 nm with a side-mode-suppression-ratio (SMSR) ≥ 15 dB, measuring as high as 40 dB, linewidth ≤110 pm, and a working power of about 3 mW. Whereas, a tuning range of 8 nm with linewidth ≤88 pm, SMSR ≥ 13 dB, reaching a maximum of 35 dB with 14.5 mW usable power is achieved from the low reflection system (LRS) at the same injection current. Moreover, an inverse relationship between the optical power and the tunability is observed in both the systems with a value as high as 180 mW exhibited by LRS configuration and attaining a tunability of 4.5 nm. Both systems highlight high stability even at higher injection currents and temperature. Such a robust, simple, and compact system may serve as a crucial light source in a plethora of diverse applications besides visible optical communications. To the best of our knowledge, this is the first report on a continuously tunable self-injection locked tunable laser system.

Performance Characterization of High and Low Power Prism based Tunable Blue Laser Diodes Systems

“…The SIL-ECDL system employing the two different LDs, viz. low-power and high-power follows the experimental set-up reported in Ref [6]. The results are plotted in Figs.…”

“…To possibly overcome the limitations of these reported approaches such as complexity, misalignment, cost, etc., a competing self-injection locking (SIL) scheme based external cavity diode laser (ECDL) system employing only a partial reflector was recently demonstrated on a green LD with a tuning range of 7.1 nm [5]. Moreover, very recently, we proposed a novel SL-ECDL system by integrating a prism and reported a record wavelength tuning range of 12 nm in blue region [6]. The system further demonstrated a side mode suppression ratio (SMSR) >13 dB, optical linewidth (Δ ) ≤ 110 pm employing a high power Fabry Perot (FP) blue LD.…”

Development of a 483 nm external cavity diode laser with cat-eye reflector

“…Properties of 455-nm GaN ECDLs with holographic and ruled gratings were also investigated [19]. A 450-nm ECDL, utilizing a self-injected locking technique and a prism, was studied for both low and high reflection systems [20]. A linewidth of a self-injection locked 446.5-nm ECDL in the sub-MHz range was achieved using a high-quality factor whispering gallery mode (WGM) cavity [21].…”