The schematic view of the two-section-DFB laser is shown in Fig. 1. The two-section DFB laser contains two sections: the active section and the reflection section. The reflection section acting as a distributed reflector, is integrated right behind the active section. Both sections contain the gratings, while only one section has current injection when the DFB laser is normally working.
Multi-channel interference (MCI) laser is a monolithic InP based widely tunable semiconductor laser, as shown in Fig. 1. The MCI laser is electronically/thermally tuned, which can address any wavelength in a range of more than 40 nm. Mode selection of the MCI laser is based on constructive interference of eight arms with unequal length difference . By injecting currents into or heating the eight arm phase sections, we can make the eight arms in phase at any desired wavelength so as to generate a narrow strong reflection peak at the desired wavelength, as shown in Fig. 2. Therefore, the MCI laser can be fabricated easily with standard photolithography, which can reduce the fabrication cost. Besides, due to the independent arm phase sections, the MCI laser is insensible to the initial phases of the eight arms, which makes the MCI laser have a large fabrication tolerance. The MCI laser has been demonstrated to have a tuning range of more than 53.6 nm and side mode suppression ratios (SMSRs) larger than 40 dB across the tuning range . By adjusting the bandgap of the MQWs, tuning range of the MCI laser can cover the whole C band or L band. Semiconductor optical amplifier (SOA) has also been successfully integrated with the MCI laser by a two port multi-mode interference reflector (MIR) . The two port MIR can be fabricated simultaneously with the deeply-etched waveguides of the MCI laser without increasing the fabrication complexity. The SOA can be used to control the output power and compensate the power variation between different channels. When reverse biased, the SOA acts as a shutter so as to enable dark tuning between channels.
Lithium niobate (LN) , which demonstrated its exceptional performance in fiber-optic communications over the past decade, has become the material of choice in high-performance electro-optic modulators. Despite having various preferable performance in optical communication, traditional bulky LN modulators have its limitations in integration size, power consumption,Vπ and so forth. To overcome these limitations, Ori-Chip has developed cutting-edge thin-film lithium niobate (TFLN) technologies1-3. Ori-Chip TFLN modulators have demonstrated superior performance including: miniaturization of chip length, >20dB extinction ratio (ER), <3.3V Vπ and so forth. These preferable properties make TFLN modulators an ideal solution for the next generation high-speed optical communication systems. Figure 1 shows a photograph of a 4-inch TFLN wafer fabricated in-house from Ori-Chip wafer fab.