Back-side-on-BOX heterogeneously integrated III-V-on-silicon O-band discrete-mode lasers

Abstract

We demonstrate foundry-fabricated O-band III-V-on-silicon discrete-mode lasers. The laser fabrication follows the back-side-on-buried-oxide laser integration process and is compatible with complex, multilayer, silicon-on-insulator based platforms. A series of devices were characterized, with the best devices producing on-chip powers of nearly 20 mW with Lorentzian linewidths below 20 kHz and a side mode suppression ratio of at least 60 dB.

Robust single frequency index-patterned laser design using a Fourier design method

“…2, how the wavelength-dependent change in threshold gain of the laser can be determined using a weighted Fourier transform of the distribution of perturbations along the device. The background theory describing the route to preferentially select a single-mode using the Fourier transform approach has been described in several previous publications [5,16,[18][19][20][21]. We describe here the key features of the method relevant to our later analysis.…”

“…In addition, the lasers have unique properties including narrow linewidth [3] and are robust against feedback [4]. The concept has recently been applied for Silicon-photonics integrated lasers [5]. The refractive perturbation can be achieved with a shallow slot or pit inserted in the waveguide [4,6].…”

“…The refractive perturbation can be achieved with a shallow slot or pit inserted in the waveguide [4,6]. The spectral content of the index-patterned laser comes from sculpting the gain profile of the individual longitudinal modes, for which a wide range of index patterns have been used [3][4][5].…”

“…Along with this, given the convergent goals of single-mode laser devices (e.g. low linewidth) and the increased availability of device components integrateable with Silicon-photonics, it would appear the separate laser design approaches will become less distinguishable [5,11,12]. Also in the field of nitride devices, where Bragg gratings are difficult and expensive to make, index-patterned devices have the ability to take the lead in terms of single-mode generation [13].…”

Supplementary document for Robust single frequency index-patterned laser design using a Fourier design method - 6327486.pdf

“…In this case, the index pattern constructed represents a discrete approximation to a continuous Fourier cosine transform of the real-space design function, corrected to allow for the variation of the amplitude of the modulation function w(ϵ) = sinh (α 1 ϵL) along the cavity. Further information on the detail of how the perturbation positions are selected to approximate to the continuous Fourier transform can be found in several publications, including [2,4], and is also described briefly in the next section. We note that the term cos (∆mπ) in Eq.…”