Spach Optics, Inc.

Mitutoyo M Plan Apo NIR 20x Objective (NA 0.40, WD 20mm, 480–1800nm, M26)

Regular price $3,600.00

SKU: 378-824-16

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The Mitutoyo M Plan Apo NIR 20× Objective is a near-infrared and short-wave infrared (SWIR) optimized plan apochromat objective from Mitutoyo’s M Plan Apo NIR series — delivering wide-area 20× magnification with an exceptional 20mm working distance and optimized transmission across an extraordinary 480–1800nm spectral range spanning the full visible, NIR, and SWIR spectrum. Ideal for wide-area NIR/SWIR survey imaging, silicon wafer inspection, Raman spectroscopy, and NIR/SWIR laser applications requiring extended working clearance and maximum spectral range at intermediate magnification.

  • 🔦 Exceptional spectral range: 480–1800nm (visible + NIR + SWIR) — transmission extending to 1800nm covers the full NIR and into the SWIR, enabling silicon wafer through-inspection, InGaAs camera imaging, SWIR fluorescence, and Raman spectroscopy with long-wavelength excitation lasers well beyond the range of standard NIR objectives (~1000nm)
  • 📏 Super long working distance: 20mm — extraordinary clearance for a 20× objective, providing ample room for specimens in environmental chambers, cryostats, vacuum systems, and laser processing setups, as well as clearance for beam delivery optics, collection systems, and environmental control hardware
  • 🔬 NA 0.40, 0.7µm resolving power — practical numerical aperture for a long working distance NIR/SWIR objective at 20×, delivering sub-micron resolution for wide-area semiconductor inspection, Raman mapping, and NIR/SWIR imaging
  • 🌟 Plan apochromat (M Plan Apo) correction — Mitutoyo’s highest level of chromatic and spherical aberration correction for accurate, flat-field imaging across the full 480–1800nm spectral range
  • ♾️ Infinity-corrected, M26 thread — compatible with Mitutoyo FS series microscopes and other infinity-corrected systems with M26 nosepieces
  • 🇯🇵 Mitutoyo quality, made in Japan — precision optical construction for consistent, high-efficiency NIR/SWIR transmission and long service life
  • Catalog number 378-824-16

🔧 Product Description

The Mitutoyo M Plan Apo NIR 20× is a wide-area survey and inspection objective from Mitutoyo’s M Plan Apo NIR series — combining plan apochromat correction, a 20mm working distance, and an extraordinary 480–1800nm spectral range that extends well into the short-wave infrared (SWIR). The 20mm working distance is exceptional for a 20× objective, providing clearance for the full range of semiconductor inspection fixtures, environmental chambers, cryostats, vacuum systems, and laser processing setups, as well as ample room for beam delivery optics and collection systems that must coexist with the imaging objective. The 1800nm upper wavelength limit enables applications that require SWIR transmission including InGaAs camera imaging, SWIR fluorescence imaging, and Raman spectroscopy with long-wavelength excitation lasers (1064nm, 1550nm). For silicon wafer inspection, the extended SWIR range enables through-silicon imaging at wavelengths where silicon is highly transparent, enabling backside inspection, subsurface defect detection, and wide-area survey of large wafer surfaces at 20× before stepping up to higher magnification for detailed inspection. At 20× with a 1.2mm field of view (with Ø24 eyepiece), this objective provides a practical balance between field of view and resolution for wide-area NIR/SWIR survey and navigation. The plan apochromat correction ensures flat-field imaging with accurate chromatic registration across the full 480–1800nm spectral range. Compatible with Mitutoyo FS series microscopes and other infinity-corrected systems with M26 thread nosepieces. Catalog number 378-824-16.


🔎 Typical Applications

  • Wide-area silicon wafer backside and through-silicon survey inspection using SWIR transparency
  • InGaAs camera imaging requiring SWIR transmission to 1800nm at 20×
  • Raman spectroscopy mapping with NIR and SWIR excitation lasers at intermediate magnification
  • SWIR fluorescence imaging of biological and materials specimens
  • Wide-area NIR/SWIR survey before stepping up to higher magnification NIR objectives
  • NIR/SWIR laser processing and beam characterization requiring long working distance at 20×

📊 Key Specifications

Specification Details
Catalog Number 378-824-16
Magnification 20×
Numerical Aperture (NA) 0.40
Immersion Medium Dry (air)
Working Distance 20mm (Super Long Working Distance)
Spectral Range 480–1800nm (Visible + NIR + SWIR)
Resolving Power 0.7µm
Focal Depth 1.7µm
Focal Length 10mm
Field of View (Ø24 eyepiece) Ø1.2mm
Real FOV (1/2" chip camera) 0.24 × 0.32mm
Optical Design M Plan Apo NIR (Plan Apochromat, NIR/SWIR-optimized)
Correction Infinity-corrected (brightfield)
Thread / Mount M26
Compatible Systems Mitutoyo FS series; other infinity-corrected M26 systems
Country of Origin Japan
SKU 378-824-16

University and institutional purchase orders are welcome. Please contact us for invoicing and procurement documentation.

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