Mita Giken Top Page                                                                                            .
Confocal Optics


This page introduces our confocal optics.
When talking about confocal optics, I am referring to the laser scanning confocal microscope (LSCM)
that takes fluorescent images, especially in the bioscience field.
LSCM is also called a confocal laser scanning microscope (CLSM).
Please note that the followings are our opinions only.


Features of Confocal Optics

Advantages
The principle is simple and easy to understand.
Toward the upstream (laser or photodetector side) of a scanner, the optics are easy to assemble
because the beam is static and its diameter can be freely changed.
An image sensor is not required, and a device such as a PMT (photomultiplier tube)
can be used (this is at the same time a drawback too).
Rays from non focal points are eliminated not only on the XY-axis
but also on the Z-axis (along the beam to reach the target).
The balance between the spatial resolution and light intensity can be adjusted by the confocal spatial filter setting.
An optical fiber can be used as a confocal spatial filter,
and the photodetector can be separated from the microscope as an independent module.
It is easy to get an appropriate spatial resolution from the total system as long as the objective lens is good enough.

Drawbacks
A scanner, scan control electronics, and signal processing electronics are necessary
because the beam is scanned.
Fast phenomena that change during a scan appear deformed.
The sampling rate and the analogue bandwidth of signal processing electronics are high.


Our Experiences and Knowledge

Laser Light Source
s
We have knowledge and experience in laser light sources in the following ways:
The selection of appropriate lasers according to the customer's application and budget.
Use of the customer's laser.
Any visible laser can be used.
Integration of mechanical shutters and attenuators.
Creating multiwavelength sources using combiners.
Real time light intensity control of each wavelength by an acousto-optic device.
Delivery by a single mode fiber or a polarization maintaining fiber.
Optics alignment training for the user.

Confocal Optics
We also have knowledge and experience in confocal optics in the following ways:
System configuration according to the application.
Both an infinity-corrected system or a finite system are possible
(Z scans are restricted to an infinity-corrected system).
The use of the customer's microscope and other optics.
The use of many parts from the manufacturers' catalogues.
Design of specifications and distances of objective lenses, tube lenses, and scan lenses.
Design of necessary mechanical adjustments and alignment procedures.
Design of the beam diameter at each position.
Calculation of the expected spatial resolution.
The collimation of a fiber delivered beam (multiwavelength is possible)
Beam diameter adjustment using a beam expander.
Design of a confocal spatial filter.
The use of optical fiber as a confocal spatial filter and as a signal light delivery system to the photodetector.
The combination of an illumination laser beam pass and a fluorescence signal light pass.
Selection of appropriate X-scanners and Y-scanners.
Scan mirror shape design according to the beam diameter and scan angle.
Scan module (body) design.
Integration of a resonant mirror or an acousto-optic deflector in a scanner.
Fiberscopes using image fiber (image bundle).
Mechanical design of adapters and tubes.
Lectures on optics and alignment training for the user.


Why Our Confocal Optics are Recommended.

Using us for your confocal optics needs has the following advantages:
The possibility to build a proper system for your applications by modular design.
Our attitude to think with the customer.
We are good at custom orders and trial manufacturing.
The possibility of lower costs compared to other manufacturers.
The user could adjust, maintain, or modify the optics by themselves
because lectures on optics and alignment training for the user are possible.



Copyright 2011, Mita Giken Co., Ltd. All rights reserved.