Integrated Lasers on Silicon at Communication Wavelength: A Progress Review

Abstract

including high refractive index contrast with its oxide material, low loss at communication wavelength regime, and significant thermo-optic coefficient for tuning. Contributed by these advantages, various photonic components have been demonstrated on integrated Si photonics platform, including mode couplers, [3][4][5][6] tunable filters, [7][8][9][10] and optical modulators. [11][12][13][14] However, Si itself is an indirect bandgap material, which limits its light emission efficiency. Laser sources on Si remain to be the challenging component for photonics integration. The requirements of an integrated laser source not only cover laser performance parameters such as optical power, threshold, pumping scheme, and stability, but also low-cost and high-volume production. Researchers are trying to come up with different ways to integrate lasers on Si. The most common way is to integrate III-V lasers on Si photonics platform, through bonding integration or direct growth approach. Alternatively, group IV materials such as germanium (Ge) and germanium tin (GeSn) alloy-based lasers show promise, with significant research progress in the past decade. Raman effect has also been explored to demonstrate lasers on Si. Such kind of laser enables lasing from the Si material itself and has drawn a lot of interest in the research community. Also, rare earth (RE) elements can be doped within photonics layer to make lasers on Si, which is similar to the idea of RE-doped optical fiber laser. RE-doped laser has the advantage of low noise and high thermal stability. Comprehensive reviews on Si-integrated lasers were published more than 6 years ago. [15,16] In the meanwhile, to the best of our knowledge, the review for the most recent progress on Siintegrated lasers covering the above-mentioned approaches is still lacking.In this review, we have summarized the recent development progress of lasers integrated on Si in the past two decades, with the focus on the wavelength regimes for communication. These lasers are categorized based on their gain media, including III-V semiconductor laser, Ge/GeSn laser, Si-based Raman laser, and RE-doped laser on Si. For III-V laser, different integration approaches are discussed, covering flip-chip integration, transfer printing integration, hybrid bonding, and direct growth method. The review is organized in the following way: it starts from background information as presented in Section 1. III-V laser, Ge/GeSn laser, Raman laser, and RE-doped laser

Advances in lithium niobate thin-film lasers and amplifiers: a review

“…At present, the way to integrate an electric pump light source based on III-V gain materials with an LNOI platform can be roughly divided into hybrid integration, heterogeneous integration, and microtransfer printing, as described below 129 – 134 …”

Prospects and applications of on-chip lasers

“…Excellent reviews of recent advances and future perspectives can be found in [12][13][14][15][16]. In this paper, we further discuss the prospects of on-chip lasers from the perspective of incorporating cutting-edge applications.…”

Highly Efficient Energy Transfer from Silicon to Erbium in Erbium-Hyperdoped Silicon Quantum Dots

“…Silicon (Si) photonics has been intensively investigated due to its excellent compatibility with Si-based complementary metal oxide semiconductor (CMOS) technologies [ 1 , 2 ]. While monolithic Si-compatible solutions for various devices such as detectors, waveguides, and modulators have been available for years, the development of Si photonics has been impeded by the lack of monolithic energy-efficient and cost-effective light sources [ 3 , 4 ]. Owing to a spectroscopically sharp and environment-stable radiative transition at the wavelength (λ) of 1.54 μm that is highly desired for Si photonics [ 5 ], Er-doped Si is an ideal material for the fabrication of light sources in Si photonics.…”