3D Sensing
3D Sensing driving need for Electrical Test of VCSELs, laser diodes and photo diodes
3D sensing augments a camera's object & facial recognition.
3D sensing enhances a camera’s ability to recognize objects and faces.
It is a depth-sensing technology that extends camera performance for facial and object recognition in applications such as augmented reality, gaming, autonomous vehicles, and many other fields.
One approach to 3D sensing is structured light, where coherent infrared light with a structured pattern is projected onto an object. The reflected pattern is then decoded to reconstruct a 3D image.
Another method is Time of Flight (ToF). In this process, an infrared light source sends out pulses, and the phase difference of the photons reflected back from an object is measured to calculate distance.
Download two detailed application notes:
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Laser Diode Array Test for 3D Sensing
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Improving Trigger Synchronization for High-Volume VCSEL Production Testing
Diode-based optical devices enable 3D sensing.
Key components of 3D sensing systems include diode-based devices such as laser diodes, HBLEDs (high-brightness LEDs), and photodiodes (PDs).
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Laser Diodes: These generate a narrow, coherent beam of light. Two main categories are edge-emitter lasers (EELs) and VCSELs (vertical cavity surface emitting lasers). VCSELs are becoming increasingly popular because of their cost efficiency, optical performance, temperature stability, and ability to form large 2D arrays for higher output. EELs, on the other hand, can operate at higher frequencies and transmit signals across hundreds of miles through optical fibre, making them essential for communication.
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HBLEDs/LEDs: These spread incoherent light over a wide angle and are the most efficient providers of high-quality white light, making them ideal for illumination. However, efficiency droop, limited modulation, and resolution constraints restrict their use in certain applications.
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Photodiodes: These devices detect light and convert it into current. Measuring very low PD currents requires sensitive instruments to fully characterize light intensity.
Learn about 10 critical tests for laser diodes used in 3D sensing applications.
Current-Voltage Made Accurate and Simple
In our webinar we look at ten common applications, from LEDs and Laser Diodes to measuring power efficiency of power management ICs and solar cells. Each case highlights how a Source Measure Unit (SMU) instrument offers unique advantages in terms of accuracy and simplicity. We show how a SMU allows you to both source and measure voltage and current using a single instrument.
Keithley Instruments for Electrical Testing
For accurate 3D sensing performance, wavelength stability across the full operating temperature range is crucial to maintain precision and minimize signal noise. Measurements of electrical efficiency, achieved through precise triggering and synchronization of pulse width and duty cycle, help optimize intensity and resolution. These parameters directly affect system heat dissipation, power use, and battery life.
Keithley Source Measure Unit (SMU) instruments support electrical tests including:
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Light intensity
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Forward voltage
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Lasing threshold current
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Quantum efficiency
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Dark current
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Kink testing
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Slope efficiency
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Thermistor resistance
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Temperature
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Capacitance
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L-I-V pulse testing
