Abstract: Various techniques are disclosed for detection systems and methods to detect an object or a recess present on a surface. For example, a detection system includes a laser light source configure to emit a laser beam, a deflector configured to deflect the laser beam by a deflection angle, a modulator configured to modulate the laser beam with a modulation frequency, a control unit configured to control the deflector and the modulator to vary the deflection angle in conjunction with the modulation frequency as a function of time according to a scanning sequence, a memory configured to store the scanning sequence and reference modulation frequencies for corresponding reference times, an optical sensor configured to detect a reflected laser beam, and a signal processor to extract and compare measured modulation frequencies of the detected reflected laser beam with reference modulation frequencies to detect an object or a recess on a surface.

Abstract: An example laser system includes a laser source to transmit a source light generated based on optical feedback provided by a laser cavity. The laser system further includes a beam-splitter to split the source light into a reference light and a split source light. The laser system further includes a modulator to modulate the split source light's frequency. The modulated light may be transmitted towards and reflected from a target. The modulator and beam-splitter may receive, frequency-modulate, and pass the reflected light to the laser cavity. The laser cavity amplifies the reflected light and transmits the amplified light toward the beam-splitter, such that the amplified light follows a same path as the reference light. The laser system further includes a detector to receive the reference light and amplified light, and detect a beating frequency as an indication of presence of the reflected light. Related methods and devices are also disclosed.

Abstract: An example laser system includes a laser source to transmit a source light generated based on optical feedback provided by a laser cavity. The laser system further includes a beam-splitter to split the source light into a reference light and a split source light. The laser system further includes a modulator to modulate the split source light's frequency. The modulated light may be transmitted towards and reflected from a target. The modulator and beam-splitter may receive, frequency-modulate, and pass the reflected light to the laser cavity. The laser cavity amplifies the reflected light and transmits the amplified light toward the beam-splitter, such that the amplified light follows a same path as the reference light. The laser system further includes a detector to receive the reference light and amplified light, and detect a beating frequency as an indication of presence of the reflected light. Related methods and devices are also disclosed.

Abstract: Various techniques are disclosed for detection systems and methods to detect an object or a recess present on a surface. For example, a detection system includes a laser light source configure to emit a laser beam, a deflector configured to deflect the laser beam by a deflection angle, a modulator configured to modulate the laser beam with a modulation frequency, a control unit configured to control the deflector and the modulator to vary the deflection angle in conjunction with the modulation frequency as a function of time according to a scanning sequence, a memory configured to store the scanning sequence and reference modulation frequencies for corresponding reference times, an optical sensor configured to detect a reflected laser beam, and a signal processor to extract and compare measured modulation frequencies of the detected reflected laser beam with reference modulation frequencies to detect an object or a recess on a surface.