Phase-Shift Bragg Grating in Silicon Using Equivalent Phase-Shift Method

Abstract

The design, fabrication, and measurement of a phase-shift Bragg grating in silicon using the equivalent phase-shift method are presented. Fabrication constrains are largely relaxed with this method, compared to that with conventional phase-shift structure using electron-beam lithography, enabling the fabrication of high-precision phase-shift gratings with low-cost lithography. We fabricated an equivalent phase-shift Bragg grating in silicon with optical-contact-lithography and interference lithography. The transmission spectrum shows that an equivalent quarter-wave phase-shift is achieved.

Wideband 20-wavelength 1.3- μ m distributed feedback semiconductor laser array using common holographic exposure

“…Moreover, the REC technique can find its potential application in other material systems such as silicon photonics 18,19 and some specially designed grating structures with unique laser performance, such as three phase shifts 20 and concavely apodization, 21 can also be easily realized with this technique. Also, it is the first time to realize such large bandwidth up to 74 nm covering nearly the entire O-band.…”

High channel count and high precision channel spacing multi-wavelength laser array for future PICs

“…It is possible for all the lasers to share the same seed grating, and then various lasers or arrays can be realized simultaneously when defining the sampling patterns. In addition to active components, the REC technique can also be applied to passive filters no matter what material is used 16 , where, similarly to the laser array, the Bragg waveguide can also be well controlled 17 . Therefore, both active and passive photonic components can be integrated on the same chip using the REC technique, and the wavelength precision of the active and passive components can be strictly guaranteed simultaneously.…”

Integrated Quarter-Wave Shifted Bragg Grating Array with Equalized Channel Spacing

“…In ordinary quarter-wave phase-shifted gratings where the phase shift is directly applied to the grating period [1], the resonant wavelength of the phase shift is altered by shifting the grating period; however, when the wavelength spacing is dense, doing so can require a sub-nanometer change in grating period making it difficult to fabricate using optical lithography. Here, instead, we use the equivalent phase shift (EPS) method [5] to make the quarter-wave shifted Bragg grating array with a better control over the resonant wavelength of the phase shift, the structure of which is schematically shown in Fig. 1(a).…”