DOI: 10.15129/b0f4afe8-fa22-444e-a29e-d9b6f754930f
title: Characterisation data for high-speed 128x128 LED array and application to optical camera communications

description: A 128x128 array of light-emitting diodes (LEDs) has been integrated by flip-chip bump bonding to a complementary metal oxide semiconductor (CMOS) driver chip with a pitch-matched array of driver elements. This dataset contains data relating to the characterisation of this device and its application to optical camera communications (OCC). The file “literature_review.zip” contains 6 csv files, each of which has two columns, where the first column is the number of pixels of a display device and the second column is the frame rate of the device measured in Hz. The files “thispaper.csv” and “thispaper_toggle.csv” hold the data for the device characterised here in streaming and toggle mode, respectively. The other files contain values found for previously reported devices, where the figures were extracted either from scientific literature and product data sheets. Each file corresponds to a certain display technology: light-emitting diodes (LED), liquid crystal displays (LCD), digital mirror devices and micro-electrical and mechanical systems (DMD/MEMS) and other technologies. The file “DAC_curve.csv” contains the optical output power of a single LED pixel in the array as a function of DAC value. The first column contains the DAC value and the second column contains the output power in Microwatts. The file “rx_histogram_250kfps.csv” refers to the received value of LED pixel (9,113) in a camera communications experiment, where each LED was sending an individual pseudorandom bit sequence of 10000 bits at a rate of 250 kfps, and the camera was recording at 800 kfps. The first column in this file is the received value for each bit, normalised to the average value of a high bit, and the second column is the frequency with which each received value was recorded. The file “eye250kfps.zip” contains data for an eye diagram of LED pixel (9,113) in a camera communications experiment, where each LED was sending an individual pseudorandom bit sequence of 10000 bits at a rate of 250 kfps, and the camera was recording at 800 kfps. It contains three csv files. The file “eye.csv” contains a 100x101 matrix, each corresponding to a pixel in the eye diagram. Each entry in this matrix contained a count of how often the received value was inside the corresponding pixel. The file “eye_xscale.csv” contains a vector of length 101 with the time value corresponding to each column of the matrix in “eye.csv”, where the time is measured in units of 1/camera framerate. The file “eye_yscale.csv” contains a vector of length 100 with the recevied value corresponding to each row of the matrix in “eye.csv”, where the received values are normalised to the average value of high bit. The file “BER_histogram.csv” contains statistics of the bit error rate (BER) across pixel rows 1 and 2 of the array, where all pixels of the entire array displayed individual pseudorandom bit sequences of 10000 bits at a rate of 250 kfps and the camera captured the subsection at a rate of 800 fps. The first column of the file is the BER, and the second column in the frequency with which each bit error rate was observed within the subsection of the array. The file “BER_histogram400kfps.csv” contains statistics of the bit error rate (BER) across pixel rows 1 and 2 of the array, where all pixels of the entire array displayed individual pseudorandom bit sequences of 10000 bits at a rate of 400 kfps and the camera captured the subsection at a rate of 800 fps. The first column of the file is the BER, and the second column in the frequency with which each bit error rate was observed within the subsection of the array. The file “BER_intensity.csv” contains the BER across pixel rows 1 and 2 of the array as a function of the time-average pixel intensity. The first column is the pixel intensity in camera ADC units and the second column in the BER. The file “pixel_histrogram.csv” contains statistics of the average pixel brightness across pixel rows 1 and 2 of the array, where all pixels of the entire array displayed individual pseudorandom bit sequences of 10000 bits at a rate of 250 kfps and the camera captured the subsection at a rate of 800 fps. The first column of the file contains the average received LED brightness (in camera analogue-to-digital converter units ADU) and the second column contains the frequency with which each brightness was observed. The file “rx_histogram_400kfps.csv” refers to the received value of LED pixel (1,26) in a camera communications experiment, where each LED was sending an individual pseudorandom bit sequence of 10000 bits at a rate of 400 kfps, and the camera was recording at 800 kfps. The first column in this file is the received value for each bit, normalised to the average value of a high bit, and the second column is the frequency with which each received value was recorded. The file “eye250kfps.zip” contains data for an eye diagram of LED pixel (1,26) in a camera communications experiment, where each LED was sending an individual pseudorandom bit sequence of 10000 bits at a rate of 400 kfps, and the camera was recording at 800 kfps. It contains three csv files. The file “eye.csv” contains a 100x101 matrix, each corresponding to a pixel in the eye diagram. Each entry in this matrix contained a count of how often the received value was inside the corresponding pixel. The file “eye_xscale.csv” contains a vector of length 101 with the time value corresponding to each column of the matrix in “eye.csv”, where the time is measured in units of 1/camera framerate. The file “eye_yscale.csv” contains a vector of length 100 with the recevied value corresponding to each row of the matrix in “eye.csv”, where the received values are normalised to the average value of high bit. The file “Waveform_toggle2Mfps.csv” contains the optical waveform recorded with a photomultiplier tube (PMT) when the array was operated in toggle mode between a full-on and a full-off pattern at 2 Mfps. The first column contains the time in microseconds and the second column contains the PMT output normalised to the average value of the pixel being on. The file “DelayColumn.csv” contains the delays between the pulses emitted by LEDs within one row of the array when operating in pulsed mode with 25 ns long pulses at a repetition rate of 1 MHz. The first column of the file contains the column number of each LED, and the second column of the file contains the delay in nanoseconds of the optical output of that pixel with respect to the electric trigger signal, where the optical output was monitored with a PMT. The file “DelayRow.csv” contains the delays between the pulses emitted by LEDs within column row of the array when operating in pulsed mode with 25 ns long pulses at a repetition rate of 1 MHz. The first column of the file contains the row number of each LED, and the second column of the file contains the delay in nanoseconds of the optical output of that pixel with respect to the electric trigger signal, where the optical output was monitored with a PMT. The file “pulsewidth_optvsel.csv” contains the measured pulse width when the device was operated in pulsed mode at a repetition rate of 10 MHz and the optical output was measured with a PMT. The first column contains the pulse width of the electrical input signal in nanoseconds, and the second column contains the measured optical pulse width in nanoseconds. The file “pulsewidth_npixel.csv” contains the measured pulse width when the device was operated in pulsed mode with 5 ns pulse duration and the optical output was measured with a PMT. The first column is the number of active pixels, the second column is the measured pulse width in nanoseconds when the repetition rate was 10 MHz, the third column is the measured pulse width at 66 MHz repetition rate, and the third column is the measured pulse width at 100 MHz repetition rate. The file “pulse_waveform.csv” contains the recorded optical waveform when the array was operated in pulsed mode with 5 ns pulse duration at 10 MHz repetition rate and the optical output was recorded with a PMT. The first column is the time in nanoseconds, the second column is the normalised PMT signal when 256 pixels were active, the third column is the normalised PMT signal when 1280 pixels were active, the fourth column is the normalised PMT signal when 2560 pixels were active, the fourth column is the normalised PMT signal when 3840 pixels were active, and the fifth column is the normalised PMT signal when 4960 pixels were active. The file “pulseenergy_npixel.csv” contains the pulse energy as a function of the number of active pixels when the array was operated in nano-second pulsed mode with 5 ns pulses at 10 MHz repetition rate. The pulse energy was derived from an average power measurement done with a power meter with 1 cm diameter active area at a distance of 3 cm from the array, and the collection efficiency of the power meter was estimated assuming a Lambertian emission pattern. The first column contains the number of active pixels and the second column contains the corresponding pulse energy. The file “load_binary.csv” contains an oscilloscope trace of the CLK_LOAD_DATA signal, which is a digital clock signal for loading data onto the LED array. The first column is the time in microseconds, and the second column is the signal in Volts. The trace was recorded while a binary pattern was loaded onto the device. The file “load_DAC.csv” contains an oscilloscope trace of the CLK_LOAD_DATA signal, which is a digital clock signal for loading data onto the LED array. The first column is the time in microseconds, and the second column is the signal in Volts. The trace was recorded while a 5-bit grayscale pattern was loaded onto the device.