Various optical systems equipped with diode laser light sources are discussed in the present application. One example system includes a diode laser light source for providing a beam of radiation. The diode laser has a spectral output bandwidth when driven under equilibrium conditions. The system further includes a driver circuit to apply a pulse of drive current to the diode laser. The pulse causes a variation in the output wavelength of the diode laser during the pulse such that the spectral output bandwidth is at least two times larger than the spectral output bandwidth under the equilibrium conditions.

Various optical systems equipped with diode laser light sources are discussed in the present application. One example system includes a diode laser light source for providing a beam of radiation. The diode laser has a spectral output bandwidth when driven under equilibrium conditions. The system further includes a driver circuit to apply a pulse of drive current to the diode laser. The pulse causes a variation in the output wavelength of the diode laser during the pulse such that the spectral output bandwidth is at least two times larger than the spectral output bandwidth under the equilibrium conditions.

A portable electronic device is operable in a particulate matter concentration mode where the portable electronic device uses a self-mixing interferometry sensor to emit a beam of coherent light from an optical resonant cavity, receive a reflection or backscatter of the beam into the optical resonant cavity, produce a self-mixing signal resulting from a reflection or backscatter of the beam of coherent light, and determine a particle velocity and/or particulate matter concentration using the self-mixing signal. The portable electronic device is also operable in an absolute distance mode where the portable electronic device determines whether or not an absolute distance determined using the self-mixing signal is outside or within a particulate sensing volume associated with the beam of coherent light. If not, the portable electronic device may determine a contamination and/or obstruction is present that may result in inaccurate particle velocity and/or particulate matter concentration determination.

We disclose a lidar system that includes a modulator-based probe-light generator and a coherent optical receiver. The probe-light generator uses tunable carrier-suppressed single-sideband modulation to generate frequency-chirped optical pulses for the optical-probe beam directed at the target. The coherent optical receiver uses a homodyne detection scheme in which a split portion of the optical-probe beam is used as an optical local oscillator signal for detecting a corresponding optical beam reflected by the target. The resulting electrical RF signals generated by the receiver can be processed, e.g., using a disclosed signal-processing method, to determine one or both of the distance to the target and the velocity of the target.

An apparatus and method for ultrafast real-time optical imaging that can be used for imaging dynamic events such as microfluidics or laser surgery is provided. The apparatus and methods encode spatial information from a sample into a back reflection of a two-dimensional spectral brush that is generated with a two-dimensional disperser and a light source that is mapped in to the time domain with a temporal disperser. The temporal waveform is preferably captured by an optical detector, converted to an electrical signal that is digitized and processed to provide two dimensional and three dimensional images. The produced signals can be optically or electronically amplified. Detection may be improved with correlation matching against a database in the time domain or the spatial domain. Embodiments for endoscopy, microscopy and simultaneous imaging and laser ablation with a single fiber are illustrated.

Disclosed herein are configurations for few-mode fiber optical endoscope systems employing distal optics and few-mode, double-clad or other optical fiber wherein the systems directing an optical beam to a sample via the optical fiber; collecting light backscattered from the sample; direct the backscattered light to a detector via the optical fiber; and detect the backscattered light; wherein the directed optical beam is single mode and the collected light is one or more higher order modes.

A device for absolute distance measurement includes a first tunable light source for emitting a first wavelength light of a first tunable frequency modulated by a first modulating frequency and a second light source for emitting a second wavelength light of a second frequency modulated by a second modulating frequency. An optical coupler couples the first wavelength light and the second wavelength light into an interferometer cavity. An interferometer detector provides an interference measurement signal based on a detected interference pattern. A demodulator unit generates a first demodulation signal based on the interference measurement signal by demodulation with the first modulating frequency and a second demodulation signal based on the interference measurement signal by demodulation with the second modulating frequency. A computation unit computes an absolute distance by evaluating the first demodulation signal acquired during a sweep of the first tunable frequency and the second demodulation signal.

The invention provides a method for calibration of an optical measurement system, which may be a heterodyne interferometer system, wherein a first optical axis and a second optical axis have a different optical path length, the method comprises: .sup.∘measuring a first measurement value along the first optical axis using a first measurement beam, .sup.∘measuring a second measurement value along the second optical axis using a second measurement beam, .sup.∘changing a wavelength of the first measurement beam and the second measurement beam, .sup.∘measuring a further first measurement value along the first optical axis using the first measurement beam with changed wavelength, measuring a further second measurement value along the second optical axis using the second measurement beam with changed wavelength, .sup.∘determining a cyclic error of the optical measurement system on the basis of the measured values, and .sup.∘storing a corrective value based on the cyclic error.

A method comprises: splitting laser light into sample light, reference light, and monitor light; routing the reference light into a reference arm of an OCT interferometer; routing the monitor light into a monitor device, which generates at least one optical monitor signal representing at least one time-dependent property of the monitor light; generating at least one electric monitor signal from the at least one optical monitor signal; illuminating in a point-shaped manner a sample with sample light, wherein the illumination point is guided on the surface of the sample along a predetermined trajectory; superimposing the light scattered by the sample with the reference light emerging from the reference arm to generate an electric OCT signal; wherein the at least one electric monitor signal and the electric OCT signal are AD-converted in alternating sequence, in each case equidistantly in time, to form a single digital data stream.

A method comprises: splitting laser light into sample light, reference light, and monitor light; routing the reference light into a reference arm of an OCT interferometer; routing the monitor light into a monitor device, which generates at least one optical monitor signal representing at least one time-dependent property of the monitor light; generating at least one electric monitor signal from the at least one optical monitor signal; illuminating in a point-shaped manner a sample with sample light, wherein the illumination point is guided on the surface of the sample along a predetermined trajectory; superimposing the light scattered by the sample with the reference light emerging from the reference arm to generate an electric OCT signal; wherein the at least one electric monitor signal and the electric OCT signal are AD-converted in alternating sequence, in each case equidistantly in time, to form a single digital data stream.