Low speckle laser array and image display thereof

An optical laser array, comprising a plurality of unit cells, each of said unit cells includes a first VCSEL device, a second VCSEL device and a third VCSEL device, each of said first, second and third VCSEL devices including:

• a substrate;
• a first-type doped distributed Bragg reflector disposed on said substrate;
• a first electrode connected to said substrate;
• an active layer disposed on said first-type doped distributed Bragg reflector;
• a second-type doped distributed Bragg reflector disposed on said active layer;
• a surface relief layer formed on a top surface of said second-type doped distributed Bragg reflector and having a surface relief indentation that has a diameter;
• a confinement member formed in the second-type doped distributed Bragg reflector and located between said surface relief layer and said active layer, said confinement member defining an aperture having an aperture diameter and being adapted for a laser beam generated by said active layer to pass therethrough;
• and
• a second electrode disposed on said surface relief layer and having an inner diameter,
• wherein an upper portion of said first-type doped distributed Bragg reflector, said active layer and said second-type doped distributed Bragg reflector form a mesa structure that is tapered from said upper portion of said first-type doped distributed Bragg reflector to said second-type doped distributed Bragg reflector and that has a bottom mesa diameter;
• wherein said bottom mesa diameter of said mesa structure is larger than a diameter of said aperture, said diameter of said aperture is larger than said inner diameter of said second electrode, and said inner diameter of said second electrode is larger than a diameter of said surface indentation of said surface relief layer;
• wherein said surface relief layer has a thickness that equals to n/4 times a wavelength of the laser beam with n being positive even numbers;
• and
• wherein said mesa structures of said first, second and third VCSEL devices respectively have first, second and third bottom mesa diameters (D1, D2 and D3), center points of said first and second VCSEL devices being spaced apart from each other by a first distance, the center point of said first VCSEL device being spaced apart from a center point of said third VCSEL devices by a second distance, and the center point of said second VCSEL device being spaced apart from said third VCSEL devices by a third distance.

A method of manufacturing an optical sensor module having a random VCSEL array, the random VCSEL array having a plurality of VCSELs, each VCSEL comprising:

• a substrate;
• a first-type doped distributed Bragg reflector disposed on said substrate;
• a first electrode connected to said substrate;
• an active layer disposed on said first-type doped distributed Bragg reflector;
• a second-type doped distributed Bragg reflector disposed on said active layer;
• a surface relief layer formed on a top surface of said second-type doped distributed Bragg reflector and having a surface relief indentation having a diameter in the range of 1.0-6.0 μm;
• a confinement member formed in the second-type doped distributed Bragg reflector and located between said surface relief layer and said active layer, said confinement member defining an aperture adapted for a laser beam generated by said active layer to pass therethrough with aperture diameter in the range of 3.0-15 μm;
• and
• a second electrode being a ring shaped p-Contact metal with inner diameter ranging from 8-17 μm and being disposed on said surface relief layer,
• wherein an upper portion of said first-type doped distributed Bragg reflector, said active layer and said second-type doped distributed Bragg reflector form a mesa structure having a bottom diameter ranging from 16-48 μm that is tapered from said upper portion of said first-type doped distributed Bragg reflector to said second-type doped distributed Bragg reflector,
• wherein said bottom mesa diameter of said mesa structure is larger than a diameter of said aperture, said diameter of said aperture is larger than said inner diameter of said second electrode, and said inner diameter of said second electrode is larger than said diameter of said surface indentation of said surface relief layer;
• and
• wherein said surface relief layer has a thickness that equals to n/4 times a wavelength of the laser beam with n being positive even integers.