3D imaging LADAR with linear array devices: laser, detector and ROIC

Abstract

This paper introduces the recent development of 3D imaging LADAR (LAser Detection And Ranging) in Mitsubishi Electric Corporation. The system consists of in-house-made key devices which are linear array: the laser, the detector and the ROIC (Read-Out Integrated Circuit). The laser transmitter is the high power and compact planar waveguide array laser at the wavelength of 1.5 micron. The detector array consists of the low excess noise Avalanche Photo Diode (APD) using the InAlAs multiplication layer. The analog ROIC array, which is fabricated in the SiGeBiCMOS process, includes the Trans-Impedance Amplifiers (TIA), the peak intensity detectors, the Time-Of-Flight (TOF) detectors, and the multiplexers for read-out. This device has the feature in its detection ability for the small signal by optimizing the peak intensity detection circuit. By combining these devices with the one dimensional fast scanner, the real-time 3D range image can be obtained. After the explanations about the key devices, some 3D imaging results are demonstrated using the single element key devices. The imaging using the developed array devices is planned in the near future.

Development of pulsed‐laser three‐dimensional imaging flash lidar using APD arrays

“…The readout integrated circuit (ROIC) is an important component of flash lidar because it performs TOF measurement of the laser pulses in the entire two‐dimensional area 81 . For the flash lidar, the time‐recording function is needed for each APD circuitry by using the ROIC.…”

“…66,[76][77][78][79][80] The readout integrated circuit (ROIC) is an important component of flash lidar because it performs TOF measurement of the laser pulses in the entire two-dimensional area. 81 For the flash lidar, the time-recording function is needed for each APD circuitry by using the ROIC. There are two primary types of ROCI structure, which are based on time-todigital-converter (TDC) and analog-to-digital converter (ADC), respectively.…”

Range imaging pulsed laser sensor with two-dimensional scanning of transmitted beam and scanless receiver using high-aspect avalanche photodiode array for eye-safe wavelength

“…The configuration is basically the same as the one reported in the past literature. 12 A photograph of the RID is shown in Fig. 8.…”

“…The RID includes a time-to-amplitude converter (TAC), and it measures the TOF by using a ramp voltage increasing in proportion to time. 12 The offset of the ramp voltage is usually fluctuated depending on the operating temperature of the circuit. To cancel the influence of this fluctuation, the RID has two TACs and outputs the two (the first and the second) range signals.…”

Demonstration on range imaging of 256 × 256 pixels and 30 frames per second using short wavelength infrared pulsed time-of-flight laser sensor with linear array receiver

“…This is conceptually true for the cases of long range imaging that need a large scanning mirror. For example, we reported the imaging results using this type of laser sensor in the past literature, 3 and the frame rate was just 2 Hz for the imaging of 128 × 128 pixels.…”