System and method for mobile device biometric add-on

A holder for a mobile device, the holder comprising:

• a base attachable to the mobile device;
• a housing rotatable relative to the base;
• and
• an optical assembly movably coupled to the base, configured to pivot about an axis relative to the base, and at least partially enclosed by the housing, the optical assembly comprising:
• two passive optical elements separated by a housing surface of the housing, a first passive optical element of the two passive optical elements corresponding with a camera of the mobile device, and a second passive optical element of the two passive optical elements corresponding with an illuminator of the mobile device, each of the first and second passive optical elements including two reflective surfaces, a first reflective surface of the two reflective surfaces angled more steeply than a second reflective surface of the two reflective surfaces, the two reflective surfaces of the first passive optical element configured to modify an optical pathway of the camera affixed to a portion of the mobile device by about 180 degrees, and the two reflective surfaces of the second passive optical element configured to modify a pathway of the illuminator of the mobile device by about 180 degrees;
• and
• a housing at least partially enclosing the single passive optical element.

A method for operating a mobile device having a camera and an illuminator, the method comprising:

• orienting a mobile device relative to a subject with a first portion of the mobile device facing the subject, wherein a second portion of the device comprises a camera and an illuminator, the first and second portions being on opposite sides of the mobile device;
• operating an optical assembly that is movably coupled to the mobile device by a base, the base comprising a housing rotatable relative to the base, the housing at least partially enclosing the optical assembly, and the optical assembly comprising two passive optical elements separated by a housing surface of the housing, a first passive optical element of the two passive optical elements corresponding with the camera of the device, and a second passive optical element of the two passive optical elements corresponding with the illuminator of the device, each of the first and second passive optical elements including two reflective surfaces, a first reflective surface of the two reflective surfaces angled more steeply than a second reflective surface of the two reflective surfaces, the two reflective surfaces of the first passive optical element configured to modify an optical pathway of the camera in a direction of the subject by about 180 degrees, and the two reflective surfaces of the second passive optical element configured to modify a pathway of the illuminator in a direction of the subject by about 180 degrees;
• and
• acquiring imaging data of the subject using the camera.