Monochromators and Spectrographs

 

Model

Focal

Length(mm)

Aperture

Resolution

(nm)

Dispersion

(nm/mm)

SpecialFeatures

SMALL SERIES

9030

100

f/3.2

1

8

Compact Monochromator

8030DC

61

f/2

8-10

52.38

Dual Channel Compact Spectrograph

9030DA

100

f/3.2

0.5

4

Double Additive and Double Subtractive

9030DS

100

f/3.2

1.0 bandpass

Effectively 0

Double Subtractive Monochromator

STANDARD SERIES

8010

200

f/3.5

0.5

4

Manual Spectrograph

9010

200

f/3.5

0.4

4

Manual Monochromator

9010F

200

f/2.6

1

4

Manual Monochromator

9055

200/250

f/3.5

0.18

3.3

Computer Controlled Monochromator/Spectrograph

9055F

200/250

f/2.5

0.4

3.3

Computer Controlled Monochromator/Spectrograph

9060

200

f/3.5f/2.7

0.15

3.3

Imaging Spectrograph

9057

500

f/8

0.1

1.79

Computer Controlled Monochromator/Spectrograph

9057F

500

f/5.9

0.1

1.79

Computer Controlled Monochromator/Spectrograph

9055DX

200 X 2

/ 250 x 2

F/3.5

0.1

1.79

Double Additive and Double Subtractive Monochromator

HIGH RESOLUTION SERIES

9040

496

f/6.9,f/5.2,f/4

0.03

1.53

High Resolution Half Meter

9040DA

500 x 2

f/6.9,f/5.2,f/4

0.02

0.76

Double Additive Half Meter

9040DS

500

f/6.9, f/5.2, f/4 

 0.03 bandpass

 Effectively 0

 Double Subtractive Meter

9490

914/1000

f/10,f/7

0.017

0.83

High Resolution One Meter

9490SD

914X2

f/10,f/7

 

0.42

Single and Double Pass

9150

1500

f/12

0.008

0.53

High Resolution1.5 Meter

9150SD

1500X2

f/12

0.005

1.25

Single and Double Pass

(9150X) 1.5m Single Echelle Spectrometer

1500

f/25

0.001

0.5

Single Pass CCD System

 

 

 

 

 

 

*ResolutionandDispersionvaluesmeasuredwitha1200lines/mmgrating

 

 

STANDARD SERIES MONOCHROMATORS - CONFIGURATION

 

 

Standard series monochromators can be configured in a number of different ways.  Note that each standard series monochromator includes a Sciencetech SS-80 variable slit assembly.  The included slit is usually mounted on the Monochromator input port.

 

Part #

Product

INPUT PORT CONFIGURATION

Standard

Front input

120-8042

Side Input Port for 9055/35/57/60

120-8030

Dual Input Ports for 9055/35/57/60

OUTPUT PORT CONFIGURATION

Standard

Front output

120-8043

Side Output Port for 9055/35/57/60

120-8031

Dual Output Ports for 9055/35/57/60

 

 

 

GRATING SELECTION

 

Grating selection is a crucial part of building a monochromator.  Each ruled or holographic grating is designed to diffract light most efficiently over a specific band of wavelengths.  Generally ruled gratings are designed with a ‘blaze’ wavelength at which the grating diffraction efficiency is a maximum.  Gratings also vary by the line density (ruled lines/mm).  The smaller a gratings line density is the larger the angular separation will be between two adjacent diffracted wavelengths.

 

A monochromator’s dispersion is a function of the monochromator’s focal length and the line density of the grating installed in the monochromator.

 

Generally each grating has a measured efficiency curve.  The efficiency curve is usually provided with the grating in Littrow condition.  Under Littrow condition the diffracted wavelength retraces the optical path of the incident radiation on the grating surface.  Sciencetech’s monochromators do not operate in Littrow condition therefore it should not be expected that the grating efficiency when installed in the monochromator will be exactly the same as the measured grating efficiency curve under Littrow condition.

 

 

MECHANICAL LIMITATIONS

 

Sciencetech’s line of Standard and Hi-Res monochromators have similar mechanical limitations below is a list of mechanical limitations related to the Sciencetech 9055 monochromator.

 

Dispersion ~= 5000 / n ; Where n = grating lines/mm

Bandwidth based on:  Dispersion * 25.4mm wide array (important if using a LDA or CCD)

Resolution based on:  50um wide input slit * Dispersion

 

 

Grating (l / mm)

75

150

300

600

1200

1800

2400

Dispersion (nm/mm)

66.6

33.3

16.7

8.3

4

2.8

2.1

Resolution (nm)

3.75

1.6

0.8

0.4

0.2

0.134

0.1

Bandwidth (nm)

1200

600

300

150

75

32.5

16.25

Maximum  Suggested Wavelength(nm)

13900

6950

3475

1737

868

579

434

Maximum Realistic Wavelength(nm)

21891

10945

5472

2736

1368

912

684

Maximum Wavelength Attainable(nm)**

25377

12688

6344

3172

1586

1057

793

 

** From sin(alpha) + sin(beta) = 10^-6 * k * n * lambda , where alpha = 90 degrees, beta = 90-25.4=64.6

 

 

MONOCHROMATOR ACCESSORIES

 

There are many accessories available for Sciencetechs line of small, standard and hi-res monochromators.  For a complete list of accessories see the products in the Modular Spectroscopy Equipment list.