Method for controlling VCSEL array to generate uniform flat-topped far field

Abstract

The invention provides a method for controlling a VCSEL array to generate a uniform flat-topped far field. The method, compared with a traditional VCSEL array, can achieve a uniform flat-top far fieldeasily under the condition that optical elements such as a diffuser and the like are not required to be arranged, thereby remarkably reducing the cost of the array and corresponding module groups while meeting the requirements of TOF measurement well and achieving the purpose that various far-field shapes can be controllably generated on one VCSEL chip so as to meet the requirements of differentapplication scenes, meanwhile. Moreover, the method has multiple beneficial effects which do not exist in the prior art.

Description

technical field [0001] The invention relates to the technical field of vertical cavity surface emitting lasers (VCSEL), in particular to a method for controlling a lensless VCSEL unit to generate a uniform flat-top far field. Background technique [0002] At present, in many smart devices such as smart phones, there is a huge market demand for flat-top infrared illumination (IR) projection modules, which play a vital role in specific applications such as TOF measurement and security camera equipment. The vertical cavity surface emitting laser (VCSEL) is the core device in the flat-top infrared illumination projection module. [0003] Existing flat-top infrared lighting projection modules generally include a combination of VCSEL arrays and optical devices such as diffusers in structure. The emission aperture of a typical VCSEL array is usually rectangular or circular. The spatial light distribution (far field) obtained by some existing control methods is usually Gaussian or ...

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Problems solved by technology

The emission aperture of a typical VCSEL array is usually rectangular or circular. The spatial light distribution (far field) obtained by some existing control methods is usually Gaussian or circular. This far field is non-uniform and cannot meet the TOF requirements. The needs of measurement, etc., so these shapes need to be changed into a rectangular or circular flat-top far field by a diffuser, that is, a uniform light intensity distribution

The above-mentioned existing module structure, due to the arrangement of optical devices such as diffusers, on the one hand has extremely strict requirements on the precision of assembly between the components, which increases the complexity of the structure and production process, and at the same time for Supporting this optical system also requires a rigid frame with sidewalls to support the VCSEL array and optics to provide a minimum spacing (typically 0.3-0.5mm) between the two components, and the total thickness of the module is usually close to 1mm , and ultimately make it difficult to further reduce the thickness and volume of mobile phones and other devices that it is specifically applied to

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