Ideal Vacuum Cube Viewing Window Plate Assembly for 9x9 Vacuum Chamber 3/8" Fused Silica

This Ideal Vacuum Cube 6x6 inch vacuum chamber fused silica viewing window plate assembly is designed to fit our 9x9x9 modular Cube chambers.

The fused silica window viewing plate assembly is our premium viewing plate assembly and is selected for experiments where improved optical clarity and extended wavelength transmissivity, beyond the visible is required.

Our high purity fused silica windows are ground and polished to optical grade on both sides with a total thickness variation (TTV) of <10µm, a surface finish of S/D 40/20, and a surface roughness of Ra < 1 nm. These windows have appreciably improved transmittance, and a wider useful wavelength range than standard glass. Characteristics include extraordinarily low refractive index variations, low birefringence values, and an ultra-low thermal expansion coefficient. Fused silica is used for transmissive optics where a high laser damage threshold is required. Fused silica is used for optics operating in the deep UV, visible, and the near infrared wavelength range.

We also offer Cube window plate assemblies and replacement window panes with standard low-iron tempered glass. Tempered glass is commonly used for general, direct observation of roughing or high-vacuum chamber processes and can be used to facilitate optical alignments of chamber components, observe degassing of fluids, or used to help teach in-vacuo processes by direct observation. The glass material is standard low-iron float glass. Surface quality and flatness is Q4 per ASTM 1036-06 and 1048-04. The low iron content of the glass results in it having a slight blueish tint. This economical glass is unsuitable for laser experiments below visible or beyond near-infrared (NIR) wavelengths.


Our Cube viewing windows employ an innovative, zero metal-to-glass contact design that holds the 3/8” thick window pane to an aluminum mounting plate. This cushioned window mounting system ensures operator safety and is less prone to leakage than other viewport window configurations, even at high vacuum pressures. Ideal Vacuum Cube windows are delivered fully assembled and use Viton O-rings and Teflon spacers. Bakeout temperatures to 150 °C are permissible.

The viewing window plate assembly is interchangeable with other Cube plates and can be added to an Ideal Vacuum Cube system anytime. The viewing window can be implemented as a fixed side, or a door (with our optional hinge assembly and hardware kit, P106868) on the Cube chamber.

The viewing window plate assembly, like all our other Cube plates, is built with our patented Taper-Seal technology which incorporates sloped sealing features to help prevent damage to the vacuum sealing surfaces. All Ideal Vacuum Cube plates are CNC milled from a single block of lightweight 6061-T6 Aluminum Alloy.

Before it ships, every viewing window plate assembly is visually inspected for window media imperfections, helium leak tested, cleaned and sealed, ensuring that it operates correctly, safely, and is ready for immediate installation upon delivery.

NOTE: All viewing windows or viewports are inherently fragile, should be handled carefully, and always inspected before use. Ideal Vacuum viewing windows are designed and rated for VACUUM ONLY and can be susceptible to thermal shock if exposed to rapid temperature changes (>10° C /min). If directing a laser beam through the window, make sure the laser’s wavelength can be reasonably transmitted through the window’s material. Please download and read all the safety warnings in the IVP Cube Viewing Window Assembly Manual.

Ideal Vacuum Cube Introduction

Our Ideal Vacuum Cube is a modular high-vacuum chamber system, conceived to enable creativity and design flexibility in vacuum chamber system construction. Cubes can be stacked together into various shapes and configurations, with interchangeable plates offering a variety of features for connections, windows, and feedthroughs. Plates include 1/4"-20 mounting threads on a standard 1" optical pattern for easy connection of hinges, posts, mounts, lenses, polarizers, and other accessories.

Durability and Versatility

The large inner dimensions and open design of Ideal Vacuum Cubes makes them perfect for many vacuum chamber applications and experiments. Vacuum Cubes are constructed of lightweight 6061-T6 aluminum alloy, allowing them to be easily transported around the lab and mounted on optical tables (unlike heavy stainless steel vacuum chambers). A patent-pending seal protective design, stainless steel thread inserts, and powder-coated outside plate finish help make the Vacuum Cube a durable tool for even the most demanding use.

Technical Details

Patented Chamber System

Our Ideal Vacuum Cubes have a patented design which features our Taper-Seal technology. Unlike other vacuum flange designs, such as, Conflat CF, KF/NW, or ISO-LF (large flange), which can be easily damaged when set on work surfaces, our Taper-Seal design protects critical sealing edges and o-rings from contact which can cause damage or contamination.

Innovative Chamber Building Blocks

Ideal Vacuum Cubes can easily be stacked together to build a complex, yet lightweight vacuum system (see graphic below). The outer edges of each vacuum cube feature hardware mounting sockets for easy cube-to-cube connections. A cube coupling kit includes the hardware needed to connect two cubes together. This allows scientists to creatively construct long or odd-shaped vacuum systems in a laboratory.

Configurable Plates and Accessories

The Vacuum Cube can be configured with a wide variety of plates and windows with many options. A Vacuum Cube can be fitted feedthroughs for electrical power, thermocouple temperature measurements, optical lasers light or imaging detectors, gas supply, or fluid flow for heat/cooling recirculation lines. Compatible standard flange styles include KF-16, KF-25, KF-40, KF-50, ISO-63, along with conlfat CF 2.75, CF 3.375, and CF 4.5 inch flanged ports. Viewing windows are also available, and custom plates can be manufactured on request. An optional hinge kit can be ordered to convert any plate into an operable door.

Applications for Ideal Vacuum Cubes

Our Ideal Vacuum Cubes are designed to implement well into optics laboratories for quick installation in laser research applications. The graphic below depicts an example laser spectroscopy laboratory setup, cavity ring down spectroscopy (CRDS) vacuum chamber system, using a 6x6x18 inch Ideal Vacuum Cube chamber. The modular design of our Ideal Vacuum Cubes make them suitable for many vacuum chamber applications:

• Vacuum Ultraviolet (VUV) Devices and Experiments
• Thermal Vacuum Testing
• Altitude Testing
• Vacuum Degassing Chamber
• High Power and Ultra Short Pulsed Lasers Research and Development
• Ion Acceleration
• RGA (Residual Gas Analyzers)
• Helium Leak Testing of Hermetic Sealed Devices With Welded In Helium Atmosphere
• Leak Detection Of Pharma Packaging
• Spectroscopy
• Molecular Ion Trap
• Cryostat Vacuum Chamber
• Beamlines

Vacuum Cube Pumping Performance

The pump down curves for several Ideal Vacuum Cube configurations are shown in the graphs below. A single 6x6x6 inch Cube can be pumped from atmosphere to 1x10^-5 Torr in 2.5 minutes and below 1x10^-6 Torr in around 15 minutes. (view curves graphic 1)
This was accomplished using a 68 liters/second turbomolecular pump backed by a 110 liters/minute (3.3 cfm) dry scroll vacuum pump.

We have also provided roughing pump down curves for popular Agilent Varian IDP-3 and SH-110 dry scroll pumps. The 6x6x6 Cube reaches base pressure of 300 mTorr for the IDP-3 (2.1 cfm) in less than 1 minute of pumping, and 50 mTorr for Agilent Varian SH-110 (3.3 cfm) in around 2 minutes. (view curves graphic 2)

On special request we can offer fully anodized plates to help with absorption of scattered light in laser research and optical applications. Anodized components do not pump down as fast as bare aluminum metal surfaces. (view curves graphic 3) A single 6x6x6 with anodized plates required 1 hour of pumping to reach 1x10^-5 Torr.