Plane grating Spectrometer PGS for application in the NIR range.

Introduction

The plane grating spectrometers are designed for application in the NIR range for specific measuring tasks. These compact and robust modules measure even thick layers with stable wavelength high resolution and the highest precision, even under extreme process conditions. InGaAs (indium-gallium-arsenide) is used as a detector material. The special combination of aspheric collimator and a focusing lens maintain a good, flat field correction of the spectral imaging.

Components of the PGS family

Blazed plane gratings
Aspheric lenses
Mono-fiber with slit as optical input
Cooled InGaAs photodiode array as opto-electronic output
Interfaces, processing software and support

Highlights

Benefits

Compact without movable parts
Permanently aligned
Robust even in harsh environments
Fast and simultaneous read-out
Permanently calibrated
High dynamic range
High light sensitivity
High reproducibility
Low temperature drift

Design

Central body made of aluminum alloy
Input fiber and detector are permanently connected to central body, providing excellent stability
Mechanically ruled or holographical exposed plane gratings
The grating surface is designed capture the light of a fiber with NA of up to 0.37

Video

Specification

	PGS 1.7-256 UC	PGS 1.7- 56	PGS 1.7-512	PGS 2.0-256	PGS 2.2-256
Optical entrance	Infrasil-quartz glass Diameter: 0.6 mm
Input round	Length: 300 mm NA = 0.22 (has to be filled for full specification) mounted in SMA-coupling, For PGS 1.7-256 UC: Use NIR-lightguides with core diameter ≥ 600 µm, NA = 0.22 to 0.37
Output linear	Slit width: 80 µm
Edge Filter	950 nm	950 nm	950 nm	1,350 nm	950 nm
Plane Grating	484 l / mm, blazed for approx. 1.2 µm	484 l / mm, blazed for approx. 1.2 µm	484 l / mm, blazed for approx. 1.2 µm	484 l / mm, blazed for approx. 1.4 µm	300 l / mm, blazed for approx. 1.4 µm
Hamamatsu Diode array	G9211-01SPL, 256 pixel	S9203, 256 pixel	S9204, 512 pixel	G9206, 256 pixel	G9206, 256 pixel
Spectral range	960–1,690 nm	960–1,690 nm	960–1,690 nm	1,340–2,000 nm	1,000–2,150 nm
Wavelength accuracy	1 nm
Temperature induced drift	< 0.012 nm/K
Mean spectral pixel pitch	Δλ_pixel ≈ 3 nm	Δλ_pixel ≈ 3 nm	Δλ_pixel ≈ 1.5 nm	Δλ_pixel ≈ 3 nm	Δλ_pixel ≈ 5 nm
Resolution	Δλ_FWHM ≈ 8 nm	Δλ_FWHM ≈ 8 nm	Δλ_FWHM ≈ 6 nm	Δλ_FWHM ≈ 8 nm	Δλ_FWHM ≈ 16 nm
Stray light	≤ 0.1 % as transmission of 10 mm water at 1,405 nm (exposure from halogen lamp)
Operating temperature	0–40 °C (standard, depending on cooling electronic)
Minimal bending radius of fiber (for storage and transport)	–	50 mm	50 mm	50 mm	50 mm
Minimal bending radius in operation (for wavelength accuracy)	–	100 mm	100 mm	100 mm	100 mm