Open architecture time of flight 3D SWIR camera operating at 150 MHz modulation frequency.

In the past two decades 3-D cameras have proven to be one of the next revolutions in machine vision. However, these devices are still an emerging technology with a particularly narrow set of commercially available devices. In this paper, the concept and execution of the first short wavelength infrared (SWIR) time-of-flight (ToF) 3-D camera system operating at a wavelength of 1550 nm is presented. By decoupling the optical and electrical components of the system in an open architecture we not only surpass many of the limitations of an on-chip integrated solution, but also can easily change the imaging device based on the requirements of the application. We achieve modulation frequencies up to 150 MHz, which exceeds the conventional values currently published for other large format modulators by about five times. This increase in the modulation frequency allows for a TOF camera with significantly higher depth resolution, while the open architecture design allows for a highly reconfigurable device that can be modified for specific working conditions.

Integrated all-optical infrared switchable plasmonic quantum cascade laser.

We report a type of infrared switchable plasmonic quantum cascade laser, in which far field light in the midwave infrared (MWIR, 6.1 µm) is modulated by a near field interaction of light in the telecommunications wavelength (1.55 µm). To achieve this all-optical switch, we used cross-polarized bowtie antennas and a centrally located germanium nanoslab. The bowtie antenna squeezes the short wavelength light into the gap region, where the germanium is placed. The perturbation of refractive index of the germanium due to the free carrier absorption produced by short wavelength light changes the optical response of the antenna and the entire laser intensity at 6.1 µm significantly. This device shows a viable method to modulate the far field of a laser through a near field interaction.