Czerny-Turner Spectrometer −Resolving the Sodium Doublet

Optical Metrology > Spectrometer

Task/System Illustration

www.LightTrans.com2

power

?

Highlights

• high-performance analysis of complex optical systems• full vectorial analysis of gratings by using rigorous algorithm (FMM)

www.LightTrans.com3

Parameter Description / Value & Unittype sodium lampmodel plane wavewavelengths characteristic doublet: 588.995 nm & 589.592 nmpolarization linear in x-direction (0°)

Specification: Light Source

www.LightTrans.com4

here

Specification: Apertures

www.LightTrans.com5

here

here

Parameter Description / Value & Unitwidth of entrance aperture 500 µmwidth of detector aperture 649 µm

Specification: Parabolic Mirrors

www.LightTrans.com6

Parameter Description / Value & Unittype parabolic mirrormaterial ideal high-reflective materialfocal length 1 mdiameter 20 mmtilt angle 5°reflectance 100%

here

Specification: Grating

www.LightTrans.com7

Parameter Description / Value & Unitgrating period 833 nmgrating height 282.4 nm (optimized for -1st order efficiency)blaze angle 18.7°grating material silver (Ag)substrate material silver (Ag)tilt angle variable

here

gratingheight

grating periodblaze angle

Specification: Detectors

www.LightTrans.com8

a, b

Position Modeling Technique Detector / Analyzerfull system

3D ray tracing 3D ray tracing system visualization

a field tracing 2D intensity (real color view)b field tracing power detection

Result: 3D Ray Tracing

www.LightTrans.com9

source screen gratingdetectoraperture

parabolicmirror 1

entrance aperture

parabolicmirror 2

for better illustration thedistances and focal length of the mirrors were reduced to 100 mm

Result: Field Tracing

analysis of sodium spectrum by tilting the spectrometer grating

www.LightTrans.com10

λ1 λ2detected power:

Result: Field Tracing

www.LightTrans.com11

λ1 λ2

width of detector aperture d2

detected power:

2D intensity:The used spectrometer setup is able to resolve the two wavelengths of

the characteristic sodium doublet.

Document & Technical Info

www.LightTrans.com12

code SPE.0002version of document 1.0

title Czerny-Turner Spectrometer − Resolving the Sodium Doublet

category Optical Metrology > Spectrometerauthor Rui Shi (LightTrans)used VL version 7.0.0.29

Specifications of PC Used for SimulationProcessor i7-4700MQ (1 CPU cores)RAM 16 GBOperating System Windows 8