Monolithically integrated erbium-doped tunable laser on a CMOS-compatible silicon photonics platform

Abstract

A tunable laser source is a crucial photonic component for many applications, such as spectroscopic measurements, wavelength division multiplexing (WDM), frequency-modulated light detection and ranging (LIDAR), and optical coherence tomography (OCT). In this article, we demonstrate the first monolithically integrated erbium-doped tunable laser on a complementary-metal-oxide-semiconductor (CMOS)-compatible silicon photonics platform. Erbium-doped AlO sputtered on top is used as a gain medium to achieve lasing. The laser achieves a tunability from 1527 nm to 1573 nm, with a >40 dB side mode suppression ratio (SMSR). The wide tuning range (46 nm) is realized with a Vernier cavity, formed by two SiN microring resonators. With 107 mW on-chip 980 nm pump power, up to 1.6 mW output lasing power is obtained with a 2.2% slope efficiency. The maximum output power is limited by pump power. Fine tuning of the laser wavelength is demonstrated by using the gain cavity phase shifter. Signal response times are measured to be around 200 μs and 35 µs for the heaters used to tune the Vernier rings and gain cavity longitudinal mode, respectively. The linewidth of the laser is 340 kHz, measured via a self-delay heterodyne detection method. Furthermore, the laser signal is stabilized by continuous locking to a mode-locked laser (MLL) over 4900 seconds with a measured peak-to-peak frequency deviation below 10 Hz.

Large-area pixelated metasurface beam deflector on a 12-inch glass wafer for random point generation

“…Photolithography is currently used as a part of the standard complementary metal-oxide-semiconductor (CMOS) fabrication process in the microelectronics industry. Besides, it has been widely used in silicon photonics for optical and electronic components patterning [14][15][16][17][18][19]. Recently, it has also been applied for large-area metasurface fabrication [20][21][22][23].…”

Single-layer active-passive Al2O3 photonic integration platform

“…Since the difference of refractive index between doped and undoped Al 2 O 3 is minimal [21], very low transition losses are expected. Furthermore, the low loss of the undoped Al 2 O 3 waveguide will permit the realization of complex integrated photonic devices [22][23][24].…”

A Silicon Photonic Data Link with a Monolithic Erbium-Doped Laser

“…Both erbiumand thulium-doped lasers are able to achieve high optical output power 37,38 , which is able to meet the challenging power budget in LIDAR systems 39,40 or ultrafast pulsed lasers 41 . Finally, common rare-earth materials, such as erbium, thulium, and holmium, have wide emission spectra enabling large wavelength range coverage 32,[42][43][44] and the potential for short pulse generation through mode-locking 26,[45][46][47][48][49] . In addition, the effectiveness of rare-earth-doped lasers on silicon is further enhanced with the availability of compact un-cooled pump laser diodes 50 and recent advances in photonics packaging 51 , which makes the co-package of the optical pump lasers easy to implement and achieve system-level compactness.…”