A vertical grating coupler is required to couple the light from the VCSEL onto the silicon photonics chip. Such vertical grating couplers have been designed to couple light from optical fibers onto silicon photonics chips [6]. However, the coupling efficiency of the single-side coupled vertical grating coupler can be further improved, and a coupling efficiency limit of 50\(\%\) applies when the structure is symmetric. In addition, the near-field mode size of the output from the VCSEL is about 6 um, smaller than the 9 um mode from an optical fiber. So a smaller grating coupler is required to couple the light from the VCSEL, which makes high-accuracy alignment more difficult to achieve during the bonding process. A bidirectional vertical grating coupler is designed to couple light from the VCSEL as shown in Fig. 1. The grating coupler is a symmetric structure with uniform gratings. Output from the VCSEL diffracts at the center of the grating coupler and couples equally into the waveguides on both sides of the grating. The top view of a microscope image of the bidirectional grating coupler is shown in Fig. 2(a). Two adiabatic tapers are used on both sides of the grating coupler to convert the mode from the VCSEL into the fundamental mode of the sub-micron waveguides. The coupled light in the two arms of the vertical grating coupler can be either used separately or recombined, depending on the application. Such bidirectional vertical grating couplers can be also made into arrays to couple light from VCSEL arrays, like shown in Fig. 2(b).