Slim IR laser for 3D optical sensing in mobile devices

By introducing a Vertical Cavity Surface Emitting Laser (VCSEL)-based flood illuminator in a slim package, ams is helping to advance the introduction of 3D sensing applications in mainstream mobile phones. The highly power-efficient 2W Merano-PD is suitable for use in the latest technologies for 3D sensing, including the time-of-flight and structured light methods.

Applications such as face recognition, augmented reality, 3D object scanning and 3D image rendering, as well as other industrial and automotive applications, will benefit from use of the Merano-PD.

"ams is the world's leading integrated manufacturer of VCSEL-based illumination modules for the mobile phone, producing both the emitter and micro-optic components in-house. This means that ams can match the components to give optimised performance, while at the same time achieving a competitive system cost and fast time-to-market for new and improved products such as MERANO-PD," said Lukas Steinmann, General Manager of the 3D Sensing, Module and Solution Business Line at ams.

Benefiting from optimised thermal design, the 2W-Merano-PD module has a footprint of 2.4x3.3mm and just 1.2mm high. It is small enough to be integrated easily into a mobile phone's design for either front- or world-facing applications. 

In a mobile optical sensing system operating on the time-of-flight principle, the MERANO-PD emits pulsed bursts of invisible IR light. A separate IR light detector senses the sequence of reflections from objects in the field of illumination and renders them as a 3D depth map or scan. The MERANO-PD may also be used in dot-pattern recognition (structured light) systems for 3D sensing, for flood illumination in IR cameras and for industrial 3D sensors and scanners. 

The high and consistent quality of the beam produced by the MERANO-PD's VCSEL emitter makes it easy to integrate into 3D sensing systems with minimal calibration. The module, which benefits from ams' deep optical expertise and its full control of the entire design, manufacturing and testing process, offers excellent uniformity of optical power distribution in the far field. The 940nm IR output, as well as the illumination pattern, is precisely controlled in the pre-defined field of illumination for best system efficiency.

The efficient VCSEL emitter and minimal optical losses in the integral diffuser mean that the MERANO-PD achieves low power consumption, limiting the amount of energy it drains from the host device's battery. This is an important benefit, as consumers continue to want long battery runtimes while setting ever higher expectations for the performance and functionality of new mobile devices. 

The MERANO-PD includes an integrated photodiode which detects impairment of the device's diffuser. When linked to a separate monitoring circuit, this means that the mobile phone can disable the illuminator for eye-safety.