A Comparison between off and On-Chip Injection Locking in a Photonic Integrated Circuit

Abstract

The mutual and injection locking characteristics of two integrated lasers are compared, both on and off-chip. In this study, two integrated single facet slotted Fabry–Pérot lasers are utilised to develop the measurement technique used to examine the different operational regimes arising from optically locking a semiconductor diode laser. The technique employed used an optical spectrum analyser (OSA), an electrical spectrum analyser (ESA) and a high speed oscilloscope (HSO). The wavelengths of the lasers are measured on the OSA and the selected optical mode for locking is identified. The region of injection locking and various other regions of dynamical behaviour between the lasers are observed on the ESA. The time trace information of the system is obtained from the HSO and performing the FFT (Fast Fourier Transform) of the time traces returns the power spectra. Using these tools, the similarities and differences between off-chip injection locking with an isolator, and on-chip mutual locking are examined.

Gain Switched Frequency Comb Enhancement Using Monolithically Integrated Mutually Coupled Lasers

“…The bias in the slotted section was set to 20 mA and current was swept across the gain section and the FP. This takes the mutually coupled system out of the asymmetric bias regime examined in [7] and [8]. At each interval the optical spectrum was recorded from the cleaved facet using an optical fibre coupled to an ANDO AQ6317B OSA.…”

“…Agrawal who observed a significant reduction in the chirp of the coupled cavity system under optimum biasing conditions [6]. On-chip coupling of monolithically integrated single mode lasers has been examined experimentally in [7] and [8] with very different configurations and design types. where, despite the lack of on-chip isolation, mutual phase locking was achieved.…”

Modulation Performance Enhancement of Directly Modulated Injection-Locked Semiconductor Lasers Using an Equivalent Electrical Circuit

“…Therefore, the OIL laser can be applied to a wide range of photonic and optoelectronic devices and systems as a high-performance optical source. cs 2021, 10, x FOR PEER REVIEW 2 of 9 potential for use as an optical transmitter in various photonic/optoelectronic applications, including high-capacity optical communications [6], microwave photonics [11], remote sensing, optical signal processing [12], and photonics integrated circuits [13]. We design and apply preprocessing electronic circuits that improve the direct modulation performance of the OIL laser.…”

“…For instance, they have an enhanced frequency response [7], improved modulation efficiency [8], high frequency stability [9], and low chirping [10]. The OIL laser has good potential for use as an optical transmitter in various photonic/optoelectronic applications, including high-capacity optical communications [6], microwave photonics [11], remote sensing, optical signal processing [12], and photonics integrated circuits [13].…”

Investigation of the Long-Term Stability of a Local Oscillator Generator Based on InP-Si3N4 Laser Source for Satellite Payloads

“…An integrated approach mitigates this increase by using an integrated light source as a reference for the comb generation and avoids the necessity to use a bulky light source. There are several examples reported in the literature of on-chip optical injection locking [21]- [22]. Nevertheless, in those works the optical injection was performed in a monolithic InP platform where the propagation losses are in the range [1,3] dB/cm, as documented in the Process Design Kits (PDKs) provided by the foundries.…”