Optical detector module and a method for operating the same

An optical detector module, comprising:

• a receiver unit;
• a transmitter unit, comprising a first light source configured to emit a first optical signal with a first peak wavelength and a second light source configured to emit a second optical signal with a second peak wavelength;
• a processor in electrical communication with the receiver unit;
• a controller in electrical communication with the receiver unit, the processor and/or the transmitter unit;
• wherein the optical detector module is configured to perform operations comprising:
• enabling, by the controller, the first light source of the transmitter unit of the optical detector module to emit the first optical signal with the first peak wavelength;
• acquiring, by the processor, a first integral value from the receiver unit corresponding to the first optical signal;
• in response to determining that the first integral value satisfies a first threshold condition, enabling, by the controller, the second light source of the transmitter unit of the optical detector module to emit the second optical signal with the second peak wavelength, wherein the first peak wavelength is different from the second peak wavelength;
• acquiring, by the processor, a second integral value from the receiver unit corresponding to the second optical signal;
• and
• identifying, by the processor and based on a comparison between the first integral value and the second integral value, a material of a target.

A method for operating an optical detector module, comprising:

• enabling, by a controller of the optical detector module, a first light source of a transmitter unit of the optical detector module to emit a first optical signal with a first peak wavelength;
• obtaining, by a processor of the optical detector module and from a receiver unit, a first background integral value corresponding to ambient light within a first reference time slot before a first target time slot;
• obtaining, by the processor and from the receiver unit, a first foreground integral value corresponding to a combination of the ambient light and the first optical signal within the first target time slot;
• obtaining, by the processor and from the receiver unit, a second background integral value corresponding to ambient light within a second reference time slot after the first target time slot;
• determining, by the processor, an average of the first background integral value and the second background integral value to obtain an averaged background integral value;
• and
• adjusting, by the processor and based on the averaged background integral value, the first foreground integral value to determine a first integral value corresponding to the first optical signal;
• and
• in response to determining that the first integral value satisfies a first threshold condition, enabling, by the controller, a second light source of the transmitter unit of the optical detector module to emit a second optical signal with a second peak wavelength, wherein the first peak wavelength is different from the second peak wavelength.