Condensers For Apertures Matching

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Description

Condensers for Apertures Matching

Condensers serve for working apertures matching at an image formation. Our condensers, being used with optical waveguide, change the entrance aperture of the beam which exits the optical waveguide and match this aperture with the entrance aperture of the spectral device.

Application of F-matcher allows:

  • Matching optical waveguide apertures with spectral devices apertures
  • Providing high quality of the image over the slit height of our spectral devices
  • Reduction of the stray light
  • F-matcher can be mounted on the exit slit of the device for collection of radiation to the waveguide

More precise information on the apertures matching principle you can find here.

Spectral image obtained with imaging monochromator-spectrograph MS5204i (grating 1800 l/mm, light source – mercury-neon lamp, multi-channel fiber bundle, fiber core diameter 200µm, CCD pixel size 24×24 µm).
a) without condenser F-matcher
b) with condenser F-matcher 2.5xUV

 Title        n-fold magnification
 
 Angle of coverage, degrees Spectral range, nm  F/number
entrance exit 
1хVIS 1 28.8° 400…2500 1:1.9 1:1.9
1хUV 1 17.5° 200…2500
200…3200 special order
1:3.3 1:3.3
1.4xUV 1.4 20.4° 200…2500
200…3200 special order
1:2.45 1:2.45
1.6xUV 1.65 27.9° 200…2500
200…3200 special order
1:2 1:3.25
2xVIS 1.92 28.8° 400…2500 1:1.9 1:3.3
2.5хUV 2.5 27.9° 200…2500
200…3200 special order
1:2 1:4.4
2.6xUV 2.6 27.9° 200…2500
200…3200 special order
1:2 1:4.4
3.6xUV 3.6 27.9° 200…2500
200…3200 special order
1:2 1:7

Possibility to complete condenser F-matcher with:

  • waveguide holder
  • 6- or 8-positional filter wheel
  • separate light filters
  • replaceable diaphragm

Recommendations for choice of F-matcher condensers for operation with fibers (NA = 0.12 and NA = 0.22) for use in monochromators-spectrographs MS series:

Monochromators-spectrographs MS series
Fiber with NA=0.12 Fiber with NA=0.22
MS 200i 1xVIS, 1xUV 1.6xUV
MS 350i 1xVIS, 1xUV 1.6xUV
MS 520i 1.4xUV 2.5xUV
MS 750i 2.5xUV 3.6xUV
MSDD 1000i 1.4xUV 2.5xUV

If you wish to use a condenser with other magnification, please consult our engineers sales@solinstruments.com

F-matcher 1xVIS 

  • Magnification – 1 fold
  • Front and back operating parts – 21 mm
  • Spectral range – 400…..2500 nm

Constructively simple and easy in operation this condenser collects radiation from the object (maximal angle of coverage is 28.8 degrees) or optical waveguide (maximal aperture Na=0.15) and transfers it to the entrance slit of the spectral device without losses and stray light. Two achromatic in a wide spectral range objectives allow obtaining a high-quality image of the waveguide end in the plane of knife blades of the entrance slit of the spectral device. Replaceable diaphragm prevents propagation of the stray light. The peculiarity of this condenser is its operating entrance aperture Na=0.15, allowing operation with the waveguides having small aperture (Na=0.12). It is constructively possible to mount a filter wheel with light filters.

 

 

 

Fig.1 Condenser F-matcher 1xVIS

 

F-matcher 1xUV 

  • Magnification – 1 fold
  • Front operating part – 44 mm
  • Back operating part – 44 mm
  • Spectral range – 220…..2500 nm
    (and up to 3200 nm on a special order)

This condenser collects radiation from the object (maximal angle of coverage is 17.5 degrees) or optical waveguide (maximal aperture Na=0.13) and transfers it to the entrance slit of the spectral device without losses and stray light. Two achromatic in a wide spectral range objectives allow obtaining a high-quality image of the object or optical waveguide end in the plane of knife blades of the entrance slit of the spectral device. Replaceable diaphragm prevents propagation of the stray light. It is constructively possible to mount a filter wheel with light filters.

The peculiarity of this condenser is its operating entrance aperture Na=0.13, allowing operation with the waveguides having small aperture (Na=0.12).

 

 

 

Fig.2 Condenser F-matcher 1xUV

 

F-matcher 2xVIS 

  • Magnification – 1.92 fold
  • Front operating part – 21 mm
  • Back operating part – 43 mm
  • Spectral range – 400…..2500 nm

Constructively simple and easy in operation this condenser collects radiation from the object (maximal angle of coverage is 28.8 degrees) or optical waveguide (maximal aperture Na=0.22) and transfers it to the entrance slit of the spectral device without losses and stray light. Two achromatic in a wide spectral range objectives allow obtaining a high-quality image of the object or optical waveguide end in the plane of knife blades of the entrance slit of the spectral device. Replaceable diaphragm prevents propagation of the stray light. It is constructively possible to mount a filter wheel with light filters.

 

 

Fig.3 Condenser F-matcher 2xVIS

 

F-matcher 1.4xUV 

  • Magnification – 1.4 fold
  • Front operating part – 34 mm
  • Back operating part – 49 mm
  • Spectral range – 200…..2500 nm
    (and up to 3200 nm on a special order)

Condenser F-matcher 1.4xUV collects radiation from the object (maximal angle of coverage is 20.4 degrees) or optical waveguide (maximal aperture Na=0.22) and transfers it to the entrance slit of the spectral device without losses and stray light. Two achromatic in a wide spectral range objectives allow obtaining a high-quality image of the object or optical waveguide end in the plane of knife blades of the entrance slit of the spectral device. Condenser operates in the wide spectral range from 200 nm up to 2500 nm, and at its operation in the range from 200 nm up to 1100 nm an improved quality of the image is provided in comparison to other condensers of F-matcher line. Replaceable diaphragm prevents propagation of the stray light. It is constructively possible to mount a filter wheel with light filters.

 

 

 

Fig.4 Condenser F-matcher 1.4xUV

 

F-matcher 1.6xUV 

  • Magnification – 1.6 fold
  • Front operating part – 24 mm
  • Back operating part – 44 mm
  • Spectral range – 200…..2500 nm (and up to 3200 nm only on a special order with increasing the price and delivery time)

Condenser 1.6хUV collects radiation from the object (maximal angle of coverage is 27.9 degrees) or optical waveguide (maximal aperture Na=0.22) and transfers it to the entrance slit of the spectral device without losses and stray light. Two achromatic in a wide spectral range objectives allow obtaining a high-quality image of the object or optical waveguide end in the plane of knife blades of the entrance slit of the spectral device. Replaceable diaphragm prevents propagation of the stray light. It is constructively possible to mount a filter wheel with light filters.

 

 

 Fig.5 Condenser F-matcher 1.6xUV
F-matcher 2.5xUV 

  • Magnification – 2.5 fold
  • Front operating part – 24 mm
  • Back operating part – 68 mm
  • Spectral range – 200…..2500 nm
    (and up to 3200 nm on a special order)

This condenser collects radiation from the object (maximal angle of coverage is 28.8 degrees) or optical waveguide (maximal aperture Na=0.22) and transfers it to the entrance slit of the spectral device without losses and stray light. Two achromatic in a wide spectral range objectives allow obtaining a high-quality image of the object or optical waveguide end in the plane of knife blades of the entrance slit of the spectral device. Replaceable diaphragm prevents propagation of the stray light. It is constructively possible to mount a filter wheel with light filters.

 

 

 

Fig.6 Condenser F-matcher 2.5xUV

 

F-matcher 2.6xUV 

  • Magnification – 2.6 fold
  • Front operating part – 23.3 mm
  • Back operating part – 74 mm
  • Spectral range – 200…..2500 nm
    (and up to 3200 nm on a special order)

Constructively simple and easy in operation this condenser collects radiation from the object (maximal angle of coverage is 28.8 degrees) or optical waveguide (maximal aperture Na=0.22) and transfers it to the entrance slit of the spectral device without losses and stray light. Two achromatic in a wide spectral range objectives allow obtaining a high-quality image of the object or optical waveguide end in the plane of knife blades of the entrance slit of the spectral device. Replaceable diaphragm prevents propagation of the stray light. It is constructively possible to mount a filter wheel with light filters.

 

 

 

Fig.7 Condenser F-matcher 2.6xUV

 

F-matcher 3.6xUV                          

  • Magnification – 3.6 fold
  • Front operating part – 24.8 mm
  • Back operating part – 101.15 mm
  • Spectral range – 200…..2500 nm
    (and up to 3200 nm on a special order)

Condenser F-matcher 3.6xUV collects radiation from the object (maximal angle of coverage is 28.8 degrees) or optical waveguide (maximal aperture Na=0.22) and transfers it to the entrance slit of the spectral device without losses and stray light. Two achromatic in a wide spectral range objectives allow obtaining a high-quality image of the object or optical waveguide end in the plane of knife blades of the entrance slit of the spectral device. Replaceable diaphragm prevents propagation of the stray light. It is constructively possible to mount a filter wheel with light filters.

 

 

Fig.8 Condenser F-matcher 3.6xUV

 

 

Condensers for Radiation Delivery

The line of image transferring devices Object – Entrance slit.

To transfer radiation from the object to the entrance slit of the spectral device image condensers are applied. Our specialists will consult you on any questions and choose for you a condenser from the listed below ones according to the tasks and working conditions you have or they will offer you a new construction optimized specially according to your demands.

Title
F/number 
 
Spectral range, nm Remarks
 
Condenser UV3.3 1:3.3 200…2500 Optimal for operation with MS350 Series
Condenser UV5.7 1:5.7 200…2500 Optimal for operation with MS520 и MSDD100 Series
Condenser UV7.0 1:7 200…2500 Optimal for operation with MS750 Series
Condenser VIS 0.8 1:0.8 400…2000 Optimal for operation with MS200 and MS350 Series
Condenser UV1.4 1:1.4 200…2500 Optimal for operation with MS200 and MS350 Series

Condenser UV3.3 

  • F/number – 1:3.3
  • Spectral range – 200…2500nm

Condenser is mounted on the entrance slit of the spectral device and transfers to it the image of the object located at a considerable distance (from 200 mm and higher) from the condenser. Achromatic objective allows obtaining a high quality image. Operating spectral range can be up to 3200 nm on a special order.

This condenser is ideal for operation with our monochromator – spectrographs MS350 Series.

 

 

 

Fig.1 Condenser UV3.3

Condenser UV5.7

  • F/number – 1:5.7
  • Spectral range – 200…2500nm

Condenser is mounted on the entrance slit of the spectral device and transfers to it the image of the object located at a considerable distance (from 200 mm and higher) from the condenser. Achromatic objective allows obtaining a high quality image. Operating spectral range can be up to 3200 nm on a special order.

This condenser is ideal for operation with our monochromator – spectrographs MS520 and MSDD1000 Series. 

 

 

Fig.2 Condenser UV5.7

Condenser UV7.0

  • F/number – 1:7
  • Spectral range – 200…2500nm

Condenser is mounted on the entrance slit of the spectral device and transfers to it the image of the object located at a considerable distance (from 200 mm and higher) from the condenser. Achromatic objective allows obtaining a high quality image. Operating spectral range can be up to 3200 nm on a special order.

This condenser is ideal for operation with our monochromator – spectrographs MS750 Series.
 

 

Fig.3 Condenser UV7.0
Condenser VIS 0.8

  • F/number – 1:0.8
  • Spectral range – 400…2000nm

Condenser is mounted on the entrance slit of the spectral device and transfers to it the image of the object located at 24 mm distance from the condenser collecting radiation in a wide angle (73 degrees). Achromatic objectives allow obtaining a high quality image.

This condenser is suitable for operation with our monochromator – spectrographs MS200 and MS350 Series.

 

 

 

Fig.4 Condenser VIS 0.8

Condenser UV1.4

  • F/number – 1:1.4
  • Spectral range – 200…2500nm

Condenser is mounted on the entrance slit of the spectral device and transfers to it the image of the object located at 23 mm distance from the condenser. Achromatic objectives allow obtaining a high quality image. Angle of coverage is 42 degrees. Operating spectral range can be up to 3200 nm on a special order.

 

This condenser is suitable for operation with our monochromator – spectrographs MS200 and MS350 Series.

 

 

 

Fig.5 Condenser UV1.4

 

Condensers for Focusing to the Detector

Image transfer units: Exit slit – Photodetector.

Image transfer units: Exit slit – Photodetector. For the transfer of radiation from the exit slit to the photodetector condensers of image are applied. Lets consider each of them in detail.

 

 

A mirror matching unit with photodetector having small receiving area.

To focus exiting radiation on the detectors with small receiving areas (diameter 2.5 – 5 mm) a special adapter with toroidal mirror is used. The advantage of it is a wide operating spectral range (from UV to IR). The view of this matching unit is given in Fig.1.

There are two variants of construction of this device:

  • Adapter is mounted directly to the spectral device exit slit the image of which is transferred to the receiving area of photodetector.
  • An optical waveguide (diameter 1 mm) is placed in the adapter, and the end of this waveguide is imaged on the photodetector.

 

 

 

Fig.1 Conjugation unit (mirror) with small size active pixel area photodetector

 A lens matching unit with photodetector having small receiving area.

  • Magnification – 0.4 – fold
  • Spectral range – 200…2500 nm

Analogically to the previous one, this adapter is used for the image transfer from the exit slit of the spectral device (maximal height 5.5 mm) to the photodetector having a small receiving area (diameter is 3 mm). Two achromatic objectives operate in a wide spectral range which may be extended up to 3200 nm on a special order. The advantage of the given construction consists in a high quality image due to which radiation losses are avoided. In Fig. 2 the image of the exit slit of the spectral device (width is 50 μm, height is 2 mm) obtained with the help of the mirror and lens matching units.

 

 

 

Fig.2 Conjugation unit (lens) with small size active pixel area photodetector

 Condenser 1xUV

  • Magnification – 1 fold
  • Spectral range – 200……3200 nm

A compact condenser is mounted directly to the spectral device exit slit (maximal operating height is 8 mm) and transfers the image to the receiving area of photodetector. Maximal angle of coverage of the condenser is 24 degrees.

 

 

 

Fig.3 Condenser 1хUV

  Condenser 1xVIS

  • Magnification – 1.04 fold
  • Spectral range – 400…2500 nm

A condenser is mounted to the spectral device exit slit (maximal operating height is 5 mm) and transfers the image to the receiving area of photodetector. Maximal angle of coverage of the condenser is 27 degrees.

 

 

 

Fig.4 Condenser 1хVIS

 Condenser 0.31xUV

  • Magnification – 0.31 fold
  • Spectral range – 200……3200 nm

An image condenser can be mounted to the spectral device exit slit (height is up to 2 mm) for the image transfer to the receiving area of photodetector (diameter is 0.6 mm). Achromatic objectives provide a high quality image. Maximal angle of coverage of this condenser is 7 degrees.

 

Fig.5 Condenser 0.31хUV

Choosing the condenser

 

Operation with the spectral devices often needs to apply auxiliary optical units for the optimization of the optical layout: collection and focusing of radiation, matching of apertures and etc. Condensersare applied to solve these tasks. Depending on the set task and conditions there are three general cases:

  • Delivery of radiation into the entrance slit of the spectral device in case when the radiation source is the end of optical waveguide. In this case a condenser is necessary for matching the optical waveguide aperture with the spectral device aperture. For this aim we offer a line of condensers for matching the apertures (F-matcher).

 

  • Radiation is delivered to the spectral device directly from the source (a lamp for example). At the same time it is necessary to collect radiation and deliver it into the spectral device without losses. This task is successfully solved by the condensers from the image transfer units: Object – Entrance slit.

 

  • Radiation at the spectral device exit is necessary to be collected and transferred to the photoreceiver without losses. Depending on the type and the size of photoreceiver an appropriate condenser can be chosen from the image transfer units: Exit slit – Photodetector.

 

 

The line of condensers for matching of apertures (F-matcher)Condensers serve for matching the working apertures at an image formation. Our condensers, being used with optical waveguide, change the entrance aperture of the beam which exits the optical waveguide and match this aperture with the entrance aperture of the spectral device.

Application of F-matcher allows:

  • Matching optical waveguide apertures with spectral devices apertures.
  • Providing high quality of the image over the slit height of our spectral devices.
  • Reduction of the stray light.

 

 

Description and operation principle   

Radiation exiting the optical waveguide is propagated within the spatial angle defined by the numerical aperture of the fiber. Effective delivery of radiation into the spectral device is difficult without special devices as a part of radiation is lost (efficiency is reduced), and there are much stray light inside the spectrograph or monochromator.

In Fig. 1 and 2 two ways of radiation delivery from the optical waveguide into the spectral device are presented. In Fig.1 a way of delivery of radiation into the entrance slit of a monochromator or spectrograph directly from the optical waveguide is demonstrated. Figure shows all drawbacks of such a technique which can be eliminated with the use of a special device for apertures matching (Fig.2). Due to such a device the exit aperture of the optical waveguide is matched with the entrance aperture of the spectral device. At the same time there is an opportunity to reduce the stray light inside the device and to use effectively all the radiation exiting the optical waveguide.

In case when the light from the optical waveguide is delivered directly into the spectral device, a part of energy is lost if the exiting angle of radiation from the optical waveguide exceeds the entrance angle of radiation to the monochromator, and\or if the fiber size exceeds the slit size. These losses can be estimated by the loss index (Li):

where
(F1/#) –  is an optical waveguide focal number,

(F2/#)- is a spectral device focal number,

V is a vignetting index which equals to 1 only in that case when the optical waveguide size is smaller than the sizes of the spectral device entrance slit; in other case V < 1.

Thus the higher is the loss index the less energy is lost at the radiation delivery. With application of our condenser matching the optical waveguide exit aperture with the spectral device entrance aperture the ratio and the loss index (Li) depends only on vignetting index V. It should be noted that as the condenser possesses a β – fold linear magnification, so the size of optical waveguide image at the entrance slit of the spectral device is correspondingly β – fold magnified. Vignetting is absent (V = 1), only when the size of optical waveguide image is smaller than the size of the spectral device entrance slit. Condenser is also can be applied at the exit of the spectral device for delivering the radiation to the optical waveguide. In this case the size of the exit slit image is β – times reduced.

 

 

Fig.1 Delivery of radiation into the spectral device directly from the optical waveguide.

Fig.2 Delivery of radiation from the optical waveguide into the spectral device with the apertures matching.

In case when the optical waveguide is a set of fibers (for example, 5 fibers, diameter of each 200 μm, distance 400 μm from each other – see Fig.3), than the entrance slit of the spectral device will obtain the image of the waveguide end. The quality of this image directly depends on the quality of imaging system – condenser.

Replaceable diaphragms in the construction of condensers F-matcher allow the maximal reduction of the stray light in the spectral device. Also there is an opportunity to install a 6- or 8-position filter wheel with replaceable light filters. All condensers of F-matcher line can be supplied with holders for the optical waveguide. These holders allow precise positioning of the waveguide end along three mutually orthogonal directions, including the direction along the optical axis.

Back parts of the condensers F-matcher can be changed according to the desirable spectral range.

Table 1 represents basic characteristics of the line of condensers F-matcher. Among them there are universal utilities for apertures matching as well as instruments developed for special working conditions.

Our specialists will consult you on any questions and choose for you a condenser from our F-matcher line according to the tasks and working conditions you have or they will offer you a new construction optimized specially according to your demands.

 

Fig.3 а). Simple double-lens condenser application

Fig.3 б). Condenser F-matcher application

For different spectral devices and optical waveguides we offer several models of condensers F-matcher.

 

Image transfer units: Object – Entrance slit.

Often radiation is delivered to the entrance slit of the spectral device directly from the source (a mercury lamp for example). Two variants are possible:

  • A radiation source (a lamp) is in a considerable distance from the entrance slit of the spectral device. In this case for more effective operation and to avoid radiation losses corrected for infinity condensers for radiation delivery are applied. This type of condensers is schematically shown in Fig.4.

 

  • A radiation source is in a minor distance from the entrance slit of the spectral device. It is reasonable to use condensers corrected for a finite distance. It allows avoiding losses when radiation is delivered to the spectral device. General description of condensers of this type is shown in Fig.5.

 

 

 

 

Fig.4

Fig.5

Image transfer units: Exit slit – Photodetector.

Radiation at the spectral device exit is often necessary to be collected and transferred to the photodetector without losses. Depending on operating conditions (the size of photodetector, working spectral range, the height of the exit slit of the spectral device) an appropriate condenser can be chosen.