High-Density Arrayed Spectrometer with Microlens Array Grating for Multi-Channel Parallel Spectral Analysis

To enable multi-channel parallel spectral analysis in array-based devices such as micro-light-emitting diodes (Micro-LEDs) and line-scan spectral confocal systems, the development of compact array spectrometers has become increasingly important. In this work, a novel spectrometer architecture based...

Full description

Saved in:
Bibliographic Details
Main Authors: Fangyuan Zhao, Zhigang Feng, Shuonan Shan
Format: Article
Language:English
Published: MDPI AG 2025-08-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/25/15/4833
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849406295758602240
author Fangyuan Zhao
Zhigang Feng
Shuonan Shan
author_facet Fangyuan Zhao
Zhigang Feng
Shuonan Shan
author_sort Fangyuan Zhao
collection DOAJ
description To enable multi-channel parallel spectral analysis in array-based devices such as micro-light-emitting diodes (Micro-LEDs) and line-scan spectral confocal systems, the development of compact array spectrometers has become increasingly important. In this work, a novel spectrometer architecture based on a microlens array grating (MLAG) is proposed, which addresses the major limitations of conventional spectrometers, including limited parallel detection capability, bulky structures, and insufficient spatial resolution. By integrating dispersion and focusing within a monolithic device, the system enables simultaneous acquisition across more than 2000 parallel channels within a 10 mm × 10 mm unit consisting of an <i>f</i> = 4 mm microlens and a 600 lines/mm blazed grating. Optimized microlens and aperture alignment allows for flexible control of the divergence angle of the incident light, and the system theoretically achieves nanometer-scale spectral resolution across a 380–780 nm wavelength range, with inter-channel measurement deviation below 1.25%. Experimental results demonstrate that this spectrometer system can theoretically support up to 2070 independently addressable subunits. At a wavelength of 638 nm, the coefficient of variation (CV) of spot spacing among array elements is as low as 1.11%, indicating high uniformity. The spectral repeatability precision is better than 1.0 nm, and after image enhancement, the standard deviation of the diffracted light shift is reduced to just 0.26 nm. The practical spectral resolution achieved is as fine as 3.0 nm. This platform supports wafer-level spectral screening of high-density Micro-LEDs, offering a practical hardware solution for high-precision industrial inline sorting, such as Micro-LED defect inspection.
format Article
id doaj-art-7350d3eea6df4c899789e6c22f829cdd
institution Kabale University
issn 1424-8220
language English
publishDate 2025-08-01
publisher MDPI AG
record_format Article
series Sensors
spelling doaj-art-7350d3eea6df4c899789e6c22f829cdd2025-08-20T03:36:26ZengMDPI AGSensors1424-82202025-08-012515483310.3390/s25154833High-Density Arrayed Spectrometer with Microlens Array Grating for Multi-Channel Parallel Spectral AnalysisFangyuan Zhao0Zhigang Feng1Shuonan Shan2Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, ChinaTsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, ChinaTsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, ChinaTo enable multi-channel parallel spectral analysis in array-based devices such as micro-light-emitting diodes (Micro-LEDs) and line-scan spectral confocal systems, the development of compact array spectrometers has become increasingly important. In this work, a novel spectrometer architecture based on a microlens array grating (MLAG) is proposed, which addresses the major limitations of conventional spectrometers, including limited parallel detection capability, bulky structures, and insufficient spatial resolution. By integrating dispersion and focusing within a monolithic device, the system enables simultaneous acquisition across more than 2000 parallel channels within a 10 mm × 10 mm unit consisting of an <i>f</i> = 4 mm microlens and a 600 lines/mm blazed grating. Optimized microlens and aperture alignment allows for flexible control of the divergence angle of the incident light, and the system theoretically achieves nanometer-scale spectral resolution across a 380–780 nm wavelength range, with inter-channel measurement deviation below 1.25%. Experimental results demonstrate that this spectrometer system can theoretically support up to 2070 independently addressable subunits. At a wavelength of 638 nm, the coefficient of variation (CV) of spot spacing among array elements is as low as 1.11%, indicating high uniformity. The spectral repeatability precision is better than 1.0 nm, and after image enhancement, the standard deviation of the diffracted light shift is reduced to just 0.26 nm. The practical spectral resolution achieved is as fine as 3.0 nm. This platform supports wafer-level spectral screening of high-density Micro-LEDs, offering a practical hardware solution for high-precision industrial inline sorting, such as Micro-LED defect inspection.https://www.mdpi.com/1424-8220/25/15/4833spectrometerspectral detectionmulti-channel spectrometerMLAGMicro-LEDline-scan spectral confocal
spellingShingle Fangyuan Zhao
Zhigang Feng
Shuonan Shan
High-Density Arrayed Spectrometer with Microlens Array Grating for Multi-Channel Parallel Spectral Analysis
Sensors
spectrometer
spectral detection
multi-channel spectrometer
MLAG
Micro-LED
line-scan spectral confocal
title High-Density Arrayed Spectrometer with Microlens Array Grating for Multi-Channel Parallel Spectral Analysis
title_full High-Density Arrayed Spectrometer with Microlens Array Grating for Multi-Channel Parallel Spectral Analysis
title_fullStr High-Density Arrayed Spectrometer with Microlens Array Grating for Multi-Channel Parallel Spectral Analysis
title_full_unstemmed High-Density Arrayed Spectrometer with Microlens Array Grating for Multi-Channel Parallel Spectral Analysis
title_short High-Density Arrayed Spectrometer with Microlens Array Grating for Multi-Channel Parallel Spectral Analysis
title_sort high density arrayed spectrometer with microlens array grating for multi channel parallel spectral analysis
topic spectrometer
spectral detection
multi-channel spectrometer
MLAG
Micro-LED
line-scan spectral confocal
url https://www.mdpi.com/1424-8220/25/15/4833
work_keys_str_mv AT fangyuanzhao highdensityarrayedspectrometerwithmicrolensarraygratingformultichannelparallelspectralanalysis
AT zhigangfeng highdensityarrayedspectrometerwithmicrolensarraygratingformultichannelparallelspectralanalysis
AT shuonanshan highdensityarrayedspectrometerwithmicrolensarraygratingformultichannelparallelspectralanalysis