Michael Belt

Arrayed narrow linewidth erbium-doped waveguide-distributed feedback lasers on an ultra-low-loss silicon-nitride platform

We demonstrate an array of erbium-doped waveguide-distributed feedback lasers on an ultra-low-loss Si(3)N(4) platform. Sidewall gratings providing the lasing feedback are defined in the silicon-nitride layer using 248 nm stepper lithography, while the gain is provided by a reactive co-sputtered erbium-doped aluminum-oxide layer. We observe lasing output over a 12 nm wavelength range (1531-1543 nm) from the array of five separate lasers. Output powers of 8 μW and lasing linewidths of 501 kHz are obtained. Single-mode operation is confirmed, with side-mode suppression ratios over 35 dB for all designs.

Erbium-doped waveguide DBR and DFB laser arrays integrated within an ultra-low-loss Si 3 N 4 platform

Record low optical threshold power and high slope efficiency are reported for arrays of distributed Bragg reflector lasers integrated within an ultra-low-loss Si(3)N(4) planar waveguide platform. Additionally, arrays of distributed feedback laser designs are presented that show improvements in pump-to-signal conversion efficiency of over two orders of magnitude beyond that found in previously published devices. Lithographically defined sidewall gratings provide the required lasing feedback for both cavity configurations. Lasing emission is shown over a wide wavelength range (1534 to 1570 nm), with output powers up to 2.1 mW and side mode suppression ratios in excess of 50 dB.

Sidewall gratings in ultra-low-loss Si 3 N 4 planar waveguides

We demonstrate sidewall gratings in an ultra-low-loss Si3N4 planar waveguide platform. Through proper geometrical design we can achieve coupling constant values between 13 and 310 cm(-1). The TE waveguide propagation loss over the range of 1540 to 1570 nm is below 5.5 dB/m.

Frequency modulated lasers for interferometric optical gyroscopes.

We study the use of frequency modulated lasers in interferometric optical gyroscopes and show that by exploiting various frequency modulation signals, the laser coherence can be controlled. We show that both angle random walk and bias stability of an interferometric optical gyroscope based on laser sources can be improved with this technique.

Integrated ultra-low-loss silicon nitride waveguide coil for optical gyroscopes

We demonstrate, for the first time, a Sagnac sensor using an on-chip 3m ultra-low-loss silicon nitride waveguide coil.

Ultra-low-loss Ta 2 O 5 -core/SiO 2 -clad planar waveguides on Si substrates

An increasing number of systems and applications depend on photonics for transmission and signal processing. This includes data centers, communications systems, environmental sensing, radar, lidar, and microwave signal generation. Such systems increasingly rely on monolithic integration of traditionally bulk optical components onto the chip scale to significantly reduce power and cost while simultaneously maintaining the requisite performance specifications at high production volumes. A critical aspect to meeting these challenges is the loss of the waveguide on the integrated optic platform, along with the capability of designing a wide range of passive and active optical elements while providing compatibility with low-cost, highly manufacturable processes, such as those found in CMOS. In this article, we report the demonstration of a record low propagation loss of 3±1  dB/m across the entire telecommunications C-band for a CMOS-compatible Ta2O5-core/SiO2-clad planar waveguide. The waveguide design, fabrication process, and optical frequency domain reflectometry characterization of the waveguide propagation loss and group index are described in detail. The losses and dispersion properties of this platform enable the integration of a wide variety of linear and nonlinear optical components on-chip, as well as integration with active rare-earth components for lasers and amplifiers and additionally silicon photonic integrated devices. This opens up new integration possibilities within the data communications, microwave photonics, high bandwidth electrical RF systems, sensing, and optical signal processing applications and research communities.

Optical Interconnect for 3D Integration of Ultra-Low Loss Planar Lightwave Circuits

We demonstrate the fabrication of a low loss broadband vertical coupler for use in the 3D integration of Si3N4 based planar waveguides. Coupling loss of 0.2 dB was achieved and interaction between layers investigated.

Integrated Sagnac optical gyroscope sensor using ultra-low loss high aspect ratio silicon nitride waveguide coil

We demonstrate operation of an interferometric optical gyroscope that uses an on-chip 3m ultra-low-loss silicon nitride waveguide coil. The measured minimum waveguide loss of the waveguide coil fabricated using lithographic die stitching was 0.78 dB/m. The angle random walk and bias instability of the gyroscope were characterized to be 8.52 deg/hr1/2 and 58.7 deg/hr respectively.

Effect of direct PRBS modulation on laser driven fiber optic gyroscope

We demonstrate that direct frequency modulation with a pseudo random bit sequence (PRBS) improves the angle random walk (ARW) and bias instability (BIS) for a laser-driven fiber optical gyroscope over a continuous wave (CW) laser driven gyroscope. The PRBS modulation is shown to improve the ARW to 0.076 deg/hr1/2 and BIS to 2.298 deg/hr compared to an ARW of 0.172 deg/hr1/2 and BIS of 5.862 deg/hr for the CW case.