Abstract: A conveyor system comprises means for conveying a sample at a controlled velocity between functions of a production line and through an interrogation zone, means for generating at least one beam of electromagnetic radiation of a terahertz frequency and directing the beam through the interrogation zone, means for detecting the electromagnetic radiation reflected from or transmitted through the sample as it moves through the interrogation zone, and means for analyzing the detected electromagnetic and for outputting a signal to at least one of the functions in dependence on the result of the analysis.

Abstract: The present invention provides, e.g., methods to recycle and/or reduce plastic, non-plastic, or a combination thereof, from a waste stream. The methods of the present invention include contacting the plastic waste with infrared (IR) energy at one or more frequencies and at one or more intensities, over a period of time effective to heat plastic present in the plastic waste.

Abstract: A Terahertz scanning imaging device for imaging objects where the object is larger than the object to imager distance. The imager comprises scanning elements, sensors, and an image processor. The scanning elements are used to direct radiation to the sensors. Multiple scanning elements and sensors may be used, each scanning a portion of the field of view. The image processor, in communication with the sensors, generates a consolidated 2-dimensional image of a field of view.

Abstract: The invention is to provide an inspection apparatus causing interactions of plural times between an object and an electromagnetic wave, thereby enabling inspection with a satisfactory sensitivity even for an object of a trace amount. The inspection apparatus detects information from an object 112 based on a change in an electromagnetic wave transmission state caused by plural times of interactions between the electromagnetic wave and the object 112.

Abstract: Strain waves of THz frequencies can coherently generate radiation when they propagate past an interface between materials with different piezoelectric coefficients. Such radiation is of detectable amplitude and contains sufficient information to determine the time-dependence of the strain wave with unprecedented subpicosecond, nearly atomic time and space resolution.

Abstract: An apparatus for analyzing, identifying or imaging an target including an integrated dual laser module coupled to a pair of photoconductive switches to produce cw signals in the range of frequencies from 100 GHz to over 2 THz focused on and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral homodyne process to generate an electrical signal representative of some characteristics of the target with resolution less than 250 MHz. The photoconductive switches are activated by laser beams from the dual laser module. The lasers in the module are tuned to different frequencies and a phase shifter in the path of one beam allows the beams to have an adjustable phase difference.

Abstract: An apparatus for investigating a sample comprising: a source of beam radiation; a detector for detecting a beam of radiation reflected by the sample and an optical subsystem for manipulating the beam between source and detector wherein the optical subsystem comprises a first optical element arranged in use to angularly deflect the source beam within a given solid angle and a second optical element arranged to focus the beam from the first optical element onto a substantially flat image plane and wherein radiation reflected by the sample passes back through the first and second optical elements to the detector.

Abstract: A method and system for detecting concealed weapons and explosives by imaging THz scenes using conventional optics and detectors is provided. Photon fields with two different wavelengths can be sent through a chopper and towards a wavelength-selective mirror. A light beam with a wavelength in the visible or IR range is sent toward a visible photon array detector. Similarly, light beams with wavelengths in the THz range can be sent towards a target, which are reflected and/or absorbed by objects in the target. The reflected or transmitted light continues on through an optional filter to remove background light, then into a non-imaging detector. The visible photon array detector can be coupled with the non-imaging detector, which will register an image of the scene that is illuminated by the THz photons.

Abstract: An optical system for detecting ice and water on the surface of an aircraft includes an elongated transparent optical element having first and second end portions. A light source and light detector are disposed in one end of the optical element and a reflective surface is disposed in the opposite end portion. The reflective surface defines a critical angle and reflects light from the light source to the light detector when the critical angle is in contact with air and refracts the light toward the external environment when the reflective surface is in contact with ice or water. The system may also incorporate an optical element wherein the reflective surface includes a continuous array of convex elements extending outwardly from and across one end of the optical element and wherein each of the convex elements defines a critical angle.

Abstract: A detecting apparatus for detecting information of a liquid object or sample includes a transmission path, a THz wave supplying unit, a THz wave detecting unit, and an infiltrative holding member for infiltration and holding of a liquid object. The supplying unit supplies an electromagnetic wave in a frequency range between 30 GHz and 30 THz to the transmission path. The detecting unit detects the THz wave transmitted through the transmission path. The infiltrative holding member is set at a location containing at least a portion in which an electric field distribution of the THz wave propagating along the transmission path extends.

Abstract: A negative refractive index device and a method of generating radiation. In one embodiment, the device includes: (1) an optical input configured to receive light and (2) an optical medium having a negative index of refraction and a second-order nonlinearity proximate a center frequency of the light, coupled to the optical input and configured to resonate in response to the light to yield radiation having a phase velocity based on a group velocity of the light.

Abstract: A method of performing dissolution analysis on a tablet, the method comprising: irradiating a tablet with radiation having at least one frequency in the range from 40 GHz to 100 THz; detecting radiation which has been transmitted through or reflected by the tablet; determining a parameter from the detected radiation indicative of the density of a coating layer of the tablet; and determining information about the dissolution characteristics of the tablet from said parameter.

Abstract: In apparatuses and methods for adjusting a distance to an object, or examining an object, by using terahertz radiation, a sensor portion and a distance changing portion are used. The sensor portion includes a generator for generating terahertz radiation, a transmission line for transmitting the terahertz radiation, and a detector for detecting the terahertz radiation transmitted through the transmission line. The distance changing portion is configured to change the distance between the object and the sensor portion. The distance is adjusted based on information of the terahertz radiation detected by the detector. The object is examined based on the information of the terahertz radiation detected by the detector, after the distance is adjusted based on the information of the terahertz radiation detected by the detector. Under a condition of the adjusted distance, leaking electromagnetic field of the terahertz radiation transmitted through the transmission line interacts with the object.

Abstract: A detector arrangement for electromagnetic radiation has at least an absorbing element and a cantilever sensor which are in operational connection with each other, so that the sensor is bendable in response to electromagnetic radiation absorbed by the absorbing element. The arrangement further includes an interferometer for measuring bending of the cantilever sensor. In a method for measuring electromagnetic radiation, electromagnetic radiation is directed on to the absorbing element and thereby bending of the cantilever sensor is caused. Bending of the cantilever sensor is measured with an interferometer. The cantilever sensor can be a door-like flap made of silicon, attached to one side of a frame of silicon.

Abstract: A non-contact thermo-elastic property measurement and imaging system and method thereof are described. Acoustic energy is incident on a first surface of a specimen under test. The acoustic energy is converted partially into heat by the specimen, causing a slight increase in the temperature in a region of interaction. The temperature increase is imaged using a high sensitivity infrared camera. Presence of defects (surface and subsurface) in the material modifies the distribution of temperature. An image of temperature distribution can be used for nondestructive testing and evaluation of materials. The temperature change in the specimen caused by acoustic excitation is related to thermal and elastic properties of the material. A measurement of the change in the temperature as a function of the amplitude of incident excitation can be used for direct measurement of thermo-elastic property of the specimen.

Abstract: A method configured to investigate an LCD structure, the method comprising: irradiating an LCD structure with pulsed radiation having at least one frequency in the range from 40G Hz to 100 THz; detecting radiation which has been transmitted through or reflected by the structure; determining information about the structure by measuring a quantity at least related to the amplitude of the detected radiation.

Abstract: This invention relates to a wide band optical gate in the terahertz domain (wavelengths in the far infrared). It comprises a first optical source (2) emitting a first beam (FTHz) in said terahertz domain, a first plate made of a semiconducting material (1) illuminated by said terahertz beam and a second optical source (3) emitting a second beam (FIR) at a wavelength capable of saturating the first plate (1) made of a semi-conducting material and making it reflective at terahertz wavelengths. This invention also relates to a system for measuring terahertz signals and to a terahertz generator. It is particularly applicable to systems for measuring terahertz signals and to terahertz generators.

Abstract: A detector for electromagnetic radiation in the range 80 GHz to 4 THz comprises a laser light source (115) an optical modulator (13) arranged to modulate light from the laser light source (11) and a filter system (17) for selecting a defined range of frequencies of the modulated light. The optical modulator is an electroabsorption modulator (13) with an antenna (15) which is sensitive to electromagnetic radiation in the range 80 GHz to 4 THz. The signal received by the antenna (15) modulates the electric field across the electroabsorption modulator (13), whereby to modulate the light from the laser light source (11).

Abstract: A method and apparatus for enhanced THz radiation coupling to molecules, includes the steps of depositing a test material near the discontinuity edges of a slotted member, and enhancing the THz radiation by transmitting THz radiation through the slots. The molecules of the test material are illuminated by the enhanced THz radiation that has been transmitted through the slots, thereby producing an increased coupling of EM radiation in the THz spectral range to said material. The molecules can be bio-molecules, explosive materials, or species of organisms. The slotted member can be a semiconductor film, a metallic film, in particular InSb, or layers thereof. THz detectors sense near field THz radiation that has been transmitted through said slots and the test material.

Abstract: A time-domain pulsed spectroscopy apparatus which has a pulsed laser light source; a splitting unit to split pulsed laser light; a pulsed-light emitting unit; a detector; a sample holder; and a sample-unit entrance and exit optical systems; wherein the time-domain pulsed spectroscopy apparatus further comprises: at least one optical-path-length varying unit for setting a photometric range; at least one optical delay unit for the wave form signal measurement; and, at least one gate member to pass or block the pulsed light to a reflector.

Abstract: The present invention provides a sensing device for obtaining information of a test sample using an electromagnetic wave including a frequency region within a frequency region of 30 GHz to 30 THz, the sensing device comprising an electromagnetic wave transmitting portion including a plurality of transmission portions (4a, 4b) for propagating electromagnetic waves and detection portions (3a, 3c) for receiving and detecting the electromagnetic waves from the plurality of transmission portions (4a, 4b), in which at least one of the plurality of transmission portions (4a, 4b) is constructed such that the test sample (5, 6) can be placed in a portion affected by an electromagnetic wave propagating therethrough.

Abstract: A vehicular vision system is disclosed comprising a high dynamic range. The systems and methods are advantages for rear vision, collision avoidance, obstacle detection, adaptive cruise control, rain sensing, exterior light control, and lane departure warning, as well as other applications where a given scene may comprise objects having widely varying brightness values.

Abstract: A method of investigating an object, comprising the steps of: (a) irradiating the object with an optically-generated pulse of electromagnetic radiation, said pulse having a plurality of frequencies in the range from 100 GHz to 100 THz; (b) detecting radiation transmitted and/or reflected from the object to obtain a time domain waveform; (c) repeating steps (a) and (b) for a plurality of points on the object and (d) combining data from step (c) to produce a time domain waveform for the object which has been averaged over the plurality of points.

Abstract: A method and an apparatus for measuring terahertz time-domain spectrum, which relate to the field of terahertz time-domain spectrum. The method comprises the steps of: generating a first pulse laser beam from a first femtosecond laser device at a preset repetition frequency to generate THz pulses; generating a second pulse laser beam from a second femtosecond laser device at the repetition frequency; measuring electric field intensities of the THz pulses at respective phase differences between the first pulse laser beam and the second pulse laser beam; and obtaining a THz time-domain spectroscopy by performing Fourier transformation of data representative of the electric field intensities. THz spectrum measured according to the method and apparatus improves spectroscopy resolution and provides a broader detection range.

Abstract: A terahertz wave detecting apparatus includes a semiconductor chip 12 in which a 2-dimensional electron gas 13 is formed at a constant position from its surface, and a carbon nanotube 14, a conductive source electrode 15, a drain electrode 16 and a gate electrode 17 provided in close contact with the surface of the chip. The carbon nanotube 14 extends along the surface of the chip, where both ends of the tube are connected to the source electrode and the drain electrode of the chip, and the gate electrode 17 is spaced at a constant interval from the side surface of the carbon nanotube. Further, the apparatus includes a SD current detecting circuit 18 for applying a voltage between the source electrode and the drain electrode and for detecting SD current therebetween, a gate voltage applying circuit 19 for applying a variable gate voltage between the source electrode and the gate electrode, and a magnetic field generating device 20 for applying a variable magnetic field to the chip.

Abstract: A method and apparatus for remotely detecting, locating, and identifying chemicals and chemical compounds through optically opaque materials. Electromagnetic radiation in the Terahertz range emitted from an antenna array is modulated to excite target molecules. The apparatus then stops the excitation energy and the molecules emit an electromagnetic signature detectable by the device at standoff distances.

Abstract: A detector system for performing at least one of transmitting and receiving electromagnetic radiation at a low-terahertz frequency. The detection of electromagnetic radiation at low-terahertz frequencies can be useful in the detection of various chemicals. Preferably a detector includes a microresonant structure that is caused to resonate by electromagnetic radiation at a low-terahertz frequency. The resonance is detected by detecting an altered path of a charged particle beam.

Abstract: There is provided a measuring apparatus including a space arrangement structure that includes space regions surrounded by conductors in a plane, an electromagnetic wave emitter that emits electromagnetic waves towards an object held by the space arrangement structure, and an electromagnetic wave detector that measures the electromagnetic waves that have passed through the space arrangement structure. Here, characteristics of the object are measured by measuring the electromagnetic waves that have passed through the space arrangement structure. The electromagnetic waves emitted from the electromagnetic wave emitter towards the space arrangement structure are incident on the plane containing the space regions at an angle, and the electromagnetic waves that have passed through the space arrangement structure are measured.

Abstract: A method of analyzing a remotely-located object includes the step of illuminating at least a portion of a targeted object with electromagnetic radiation to induce a phase transformation in the targeted object, wherein the phase transformation produces an emitter plasma, which emits terahertz radiation. The method also includes the step of ionizing a volume of an ambient gas to produce a sensor plasma by focusing an optical probe beam in the volume and the step of detecting an optical component of resultant radiation produced from an interaction of the focused optical probe beam and the terahertz radiation in the sensor plasma. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a characteristic fingerprint of the targeted object imposed onto the terahertz radiation produced as a result of the induced phase transformation.

Abstract: A method of measuring methanol vapor concentration on a real-time basis and a methanol vapor concentration measuring apparatus used in fuel cells. The method of measuring methanol vapor concentration involves using an absorption spectrometry technique, that is, after measuring intensities I0 and I1 of light of a laser before and after passing through a space filled with methanol vapor and into which light is irradiated, the methanol vapor concentration is calculated by substituting the intensities I0 and I1 into an equation defined as I1/I0=exp (K·L·C), where K represents the absorption coefficient, L represents the length of the space through which the laser passes, and C represents the methanol vapor concentration.

Abstract: Temperature measurement using a pyrometer in a processing chamber is described. The extraneous light received by the pyrometer is reduced. In one example, a photodetector is used to measure the intensity of light within the processing chamber at a defined wavelength. A temperature circuit is used to convert the measured light intensity to a temperature signal, and a doped optical window between a heat source and a workpiece inside processing chamber is used to absorb light at the defined wavelength directed at the workpiece from the heat source.

Abstract: A security inspection system is provided. The security inspection system includes a source configured to transmit a beam of radiation comprising a frequency of at least about 10 GHz. The system also includes an optical system configured to focus the beam of radiation on a sample. The system further includes at least one detector configured to detect one or more reflected beams from different locations of the sample in a focal plane of the optical system and generate a corresponding output signal. The system also includes a processor coupled to the at least one detector and configured to reconstruct a three dimensional image of the sample based upon the output signal.

Abstract: A first frequency of electromagnetic radiation and a second frequency of electromagnetic radiation are received at a detector. The first and second frequencies of electromagnetic radiation are transmitted through a medium within a frequency range of approximately 0.1 TeraHertz to approximately 10 TeraHertz. Signals are generated that are proportional to the transmittance of the frequencies of electromagnetic radiation through the medium. A ratio of the of the signals is formed, and one or more of a relative humidity, an absolute humidity, and a water vapor concentration of the medium are calculated as a function of a temperature of the medium, the ratio, and a set of functional parameters associated with the temperature of the medium.

Abstract: A single-photon detector is disclosed that provides reduced afterpulsing without some of the disadvantages for doing so in the prior art. An embodiment of the present invention provides a stimulus pulse to the active area of an avalanche photodetector to stimulate charges that are trapped in energy trap states to detrap. In some embodiments of the present invention, the stimulus pulse is a thermal pulse.

Abstract: A method of investigating a sample (breast tissue) (27), the sample comprising at least a first material (normal breast tissue) in order to determine they presence of at least one further material (cancerous tissue), the method comprising the steps of: Irradiating the sample with electromagnetic radiation in the range from 25 GHz to 100 THz; Detecting radiation reflected from the sample; Determining a parameter related to the amplitude of the radiation, which is reflected from the sample, in the time domain; Analyzing the parameter derived in step (c) in order to determine if the sample further comprises the at least one further material wherein the irradiating and reflected radiation passes through a (z-cut quartz) window member (43) having a refractive index that falls between the refractive indices of the at least first and at least one further materials.

Abstract: A specimen testing element, a specimen information obtaining method and a specimen testing apparatus is used to obtain information on a specimen by utilizing a specific phenomenon attributable to wavelength selectivity, resonance characteristics and so on. The specimen testing element obtains information on a specimen by utilizing a change in the propagation state of an electromagnetic wave propagating through a transmission path due to the existence of a specimen. A plurality of holding portions capable of holding a specimen are arranged substantially in a predetermined mode of regularity in part of a region in the transmission path where the propagating electromagnetic wave exists to form a specimen holding body. The specimen is filled in the plurality of holding portions by a specimen filling means and the electromagnetic wave propagating through the transmission path is detected by an electromagnetic wave detecting means.

Abstract: The mode-locking frequencies of two femtosecond laser light sources are controlled so that they are stabilized at high degree and the difference between the mode-locking frequencies is constant. The output of the laser light sources are used as a pumping light for generating terahertz pulses and a probe pulse light for terahertz detection. Since the time delay timings of the terahertz pulses and the probe pulse light the pulse periods of which are slightly different from each other shift from each other and the difference increases. Therefore, the temporally expanded terahertz pulses are measured by high-speed sampling without using any mechanical stage for time delay scanning. The terahertz electric field time waveform measured by high-speed sampling with the measurement time window of the pulse period is subjected to time-scale conversion and Fourier transform.

Abstract: A method for generating terahertz radiation includes inducing a background plasma in a volume of a gas by focusing a first optical beam in the volume, and generating pulsed terahertz radiation with enhanced generation efficiency by focusing a second time-delayed optical beam in the background plasma. The method may be implemented in a system for detecting and analyzing a remotely-located object.

Abstract: Hand held infrared measurement devices are disclosed, having at least two separated laser sighting emitters (2), which together mark and define a sighting area on a target surface (7,7?,7?). In an embodiment of the invention, separate lasers (2) are provided which each produce a beam (6) used to illuminate a respective separate optical beam directing element (4), mounted between each laser emitter and the target surface (7,7?,7?). The element may be, for example, any of the optical glass fibers, a prism, or a lens, such as a diffraction beam splitter lens, or a refractive lens, each element directing laser light onto the target surface to produce a visually perceptible target marking. The element is preferably made of optical material such as glass or plastic (e.g., methyl methacrylate). Separate laser emitters permit greater brightness displayed on the target within safe operation limits than use of a single laser alone, even with a beam splitter.

Abstract: Disclosed is a method and apparatus for detecting the type of anesthetic gas. The method comprises the steps of: generating a light with a plurality of wavelengths, the light being able to be separated to a plurality of light beams whose central frequencies correspond to the plurality of wavelengths; passing said light through a gas chamber, wherein, the gas chamber being filled with said anesthetic gas, said anesthetic gas having absorption characteristic with respect to said plurality of light beams; detecting the light intensity of the attenuated light beams transmitted from the gas chamber respectively, to obtain the relative absorption characteristic of said attenuated light beams, which attenuated light beams having been absorbed by said anesthetic gas; and determining the type of said anesthetic gas based on the relative absorption characteristic between said attenuated light beams.

Abstract: The terahertz camera has a fixed objective lens (2) and a plurality of detectors (3) positioned at the focal plane of the objective lens (2). Each of the detectors (3) is mounted on a movable support (10) so that the antenna is capable of movement across the focal plane of the objective lens (2) and is provided with a flexible waveguide (4) for connecting the output of the detector (3) with signal processing means. Each detector (3) is also provided with a retroreflector (6) which is reflective at frequencies other than terahertz frequencies. During use of the camera, the retroreflector (6) of each detector (3) is illuminated at non-terahertz frequencies so that the spatial position of each detector (3) and hence the spatial source of signals generated by the detector can be accurately identified. The terahertz camera is particularly suited for use in security installations and in chemical and food processing industries.

Abstract: A terahertz spectrometer having a wider range of terahertz radiation source, high temporal resolution of scanning (<0.0.099 ?m or ˜0.3 pico second) over a wider range of scanning (up to ˜100 pico seconds). Also disclosed are exemplary applications of the spectrometer in biomedical, biological, pharmaceutical, and security areas.

Abstract: In an inspection of a semiconductor wafer for a defect, when infrared light passing through a semiconductor wafer is imaged by a camera and an inspection is conducted using the image, a problem that halation occurs in the camera due to light leaking from the side of the inspection object, which makes it impossible to conduct an inspection at the periphery portion occurs. An inspection object is irradiated by an infrared light source, and transmitted light is imaged by an infrared camera to be conducted. With the use of mask means that secures a clearance from the end portion on the outer side, it is possible to inspect on the peripheral portion. Also, as means for supporting the object, plural sets of those configured to be capable of evacuating are used, and by allowing the plural sets to evacuate alternately, it is possible to inspect across the entire surface.

Abstract: The present invention provides a device, system, and associated methods to actively or passively sample air by directing it onto the surface of a porous light-absorbing semiconductor, for example, a desorption/ionization on porous silicon (“DIOS”) chip. Upon adsorption of an analyte, the surface may be analyzed directly by laser desorption/ionization time-of-flight mass spectrometry. Because the process of laser desorption/ionization and subsequent mass detection does not require elevated temperatures, thermal degradation of analytes is avoided.

Abstract: In a bolometer-type THz-wave detector 1 in a micro-bridge structure in which a temperature detecting portion 14 (diaphragm) including a bolometer thin film 7 is supported by a supporting portion 13 in a state suspended from a circuit substrate, a member (dielectric cover 11) made of a dielectric material for efficiently collecting a THz wave is added to an upper part of the temperature detecting portion 14, and when a refractive index of the dielectric cover 11 is n, thickness is t, and a wavelength of the THz wave is ?, a setting is made so as to have at >?, and a gap between the dielectric cover 11 and the temperature detecting portion 14 is set at integral multiples of ?/2. By this arrangement, an absorptance of the THz wave can be improved using a structure and manufacturing method of a bolometer-type infrared detector, and a high-performance bolometer-type THz-wave detector can be manufactured with a high yield.

Abstract: The corrosion rate of a metal immersed in a fluid medium is measured by transmission of a beam of radiation normally in the visible or near infra-red portion of the spectrum, through a thin film of the metal immersed in the medium. The film of the metal is suitably supported on a radiation-transmitting substrate such as a glass plate or slide. The corrosion rate can be determined by passing a radiation beam through the metal film sample using a twin beam system to compensate for instrument factors such as the absorbance by the fluid medium, the cell windows and the film-supporting substrate. As the thickness of the film decreases, the reduction in film thickness is determined by the increase in beam intensity, using a reference beam to compensate for the instrument factors.

Abstract: First and second thermal sensors measure the respective temperatures of portions of a surface of a structure such as an aircraft component. An alert signal is emitted if the temperatures of the surface portions are substantially different. An energy source causes heat flow within the structure. Subsurface irregularities such as disbanded areas between composite layers and foreign materials obstruct heat flow within the structure and cause proximate surface portions to exhibit different temperatures. A non-alert signal may be emitted if the temperatures of proximate surface portions are essentially the same.

Abstract: A method for measuring the timing of a flash event including capturing a first image prior to the commencement of a flash event. Capturing a second image during the occurrence of the flash event, and comparing the second image to the first image to determine a time related characteristic of the flash event.

Abstract: A method of identifying a flaw in a part is provided that includes vibrating a part to induce heat. The heat originates in any flaws in the part. A thermal image is obtained using, for example, an infrared camera. A mathematical representation of the thermophysics, such as the heat conduction or thermal energy equations using the boundary element method or finite element method is used to identify a source and an intensity of the heat identified with the thermal image. Using the source and intensity of the heat, flaw characteristics for the part can be determined. The method is employed using an inspection system that includes a vibration device for vibrating the part. An imaging device, such as an infrared camera, measures temperature on the surface of the part. An assumption is made or additional measurements are taken to obtain values for surface flux or surface heat transfer coefficients. A processor communicates with the imaging device for receiving the surface temperature.

Abstract: Vehicle-based lidar systems and methods are disclosed using multiple lasers to provide more compact and cost-effective lidar functionality. Each laser in an array of lasers can be sequentially activated so that a corresponding optical element mounted with respect to the array of lasers produces respective interrogation beams in substantially different directions. Light from these beams is reflected by objects in a vehicle's environment, and detected so as to provide information about the objects to vehicle operators and/or passengers.