Ø1/4" Diaphragm Shutters

Ø1/4" Leaf Shutters
Shutter Blades Open from the Center
Uncoated or PTFE-Coated Stainless Steel Blades
Manual or TTL Input Control

SC22

Compact Controller for Ø1/4" Diaphragm Shutter

SHBH025

Ø1/4" Shutter, Uncoated Blades

SHBH025T

Ø1/4" Shutter, PTFE-Coated Blades

SC30

Benchtop Shutter Controller
(Not to Scale)

Related Items

Ø1/2" Diaphragm Shutters

Ø1" Diaphragm Shutters

Single-Blade Beam Shutters

CMOS Cameras

Motorized Iris

Liquid Crystal Optical Shutters

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Overview
Specs
Graphs
SC22 Controller
SC30 Software
Pin Diagrams
Feedback

Shutter Selection Guide
Diaphragm	Single-Blade	Liquid Crystal
Ø1/4" Motorized	Ø0.29" Manual	Ø20 mm Liquid Crystal
Ø1/2" Motorized	Ø1/2" and Ø1" Motorized
Ø1" Motorized	Ø1/2" and Ø1" Motorized

Features

Diaphragm with Ø1/4" Clear Aperture
Available with Uncoated or Low-Reflectivity PTFE-Coated Stainless Steel Blades
Shutter Controllers Available (Sold Separately Below)
Operating Frequency of 15 Hz in Continuous Operation, Up to 50 Hz for a Limited Amount of Time
Controllers with Safety Features That Include:
- Interlock for Laser Safety Lockout and Other Applications
- Shutdown Upon Detection of Blade Jam or Other Operation Failure (Item # SC22)
- Over-Heating Protection
Mounting Adapter Available for 30 mm Cage and Ø1/2" Post Compatibility

Click to Enlarge

View Imperial Product List

Item #	Qty	Description
SHBH025	1	Ø1/4" Stainless Steel Diaphragm Optical Beam Shutter
SHCP025	1	30 mm Cage and Post Mounting Adapter for SHBH025(T) Optical Beam Shutter, 8-32 Tap
CP33	1	SM1-Threaded 30 mm Cage Plate, 0.35" Thick, 2 Retaining Rings, 8-32 Tap
TR2	1	Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 2"
ER2	4	Cage Assembly Rod, 2" Long, Ø6 mm

View Metric Product List

Item #	Qty	Description
SHBH025	1	Ø1/4" Stainless Steel Diaphragm Optical Beam Shutter
SHCP025/M	1	30 mm Cage and Post Mounting Adapter for SHBH025(T) Optical Beam Shutter, M4 Tap
CP33/M	1	SM1-Threaded 30 mm Cage Plate, 0.35" Thick, 2 Retaining Rings, M4 Tap
TR20/M	1	Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 20 mm
ER2	4	Cage Assembly Rod, 2" Long, Ø6 mm

Figure 1.1 We offer mounting adapters for compatibility with Ø1/2" posts and 30 mm cage systems.

Thorlabs' SHBH025 and SHBH025T Ø1/4" Diaphragm (Leaf) Optical Beam Shutters each feature a Ø1/4" clear aperture, two stainless steel shutter blades that open from the center of the aperture, and compact housing. The blades in the SHBH025 shutter are uncoated, and the blades in the SHBH025T shutter have low-reflectivity PTFE coating. These patented (US Patent: 9,671,676) shutters have a fast response time and can be operated using the SC22 controller either by manual pushbutton or external 0 to 5 V TTL signal. For the version with PTFE-coated blades, the coating is deposited on both sides of the blades to reduce reflections from the closed aperture while maintaining the performance of the uncoated shutter. A plot of the typical reflectance of the coating as a function of wavelength can be seen on the Graphs tab. Each shutter has a 35" cable with a 4-pin mini-DIN male connector to connect the shutter to a SC22 or SC30 controller.

Operation
The shutter is open while the voltage signal from the controller is high, and the shutter is closed while the voltage signal is low. The SHBH025(T) shutter has an internal Hall sensor that outputs the shutter state. The maximum continuous operating frequency should be limited to 15 Hz, though the unit can operate up to 50 Hz for up to one minute. If the time limit is exceeded or the modulation frequency exceeds 50 Hz, the shutter lifetime will be affected. Please see the SC22 Controller tab for additional details on operation with the SC22 controller and the Specs tab for a detailed timing diagram.

Note: The blades on these shutters can move freely when the shutters are turned off. Click here for fail-safe (safety) shutters that are closed by default and only open when a signal is sent to the shutter.

Shutter Controllers
The SC22 shutter controller (sold separately below) offers a simple interface for operating the shutter. Power and Status LEDs indicate the shutter state, a BNC connector accepts an external TTL signal, and a 2.5 mm mono jack interlock output is provided. The 2.5 mm mono plug is not included but is available upon request. The controller has a compact 3.00" x 3.50" x 1.38" housing. A universal power supply for 100 - 240 VAC, 47 - 63 Hz is provided with the controller, along with a location-specific AC power cord. The controller has a 4-pin mini-DIN shielded female shutter interface connector. During manual operation, buttons on the controller are used to control the shutter state. During external modulation, the applied TTL signal controls the shutter state and can drive the shutters at burst frequencies higher than their continuous operation frequencies. The SC22 controller is programmed for use with the SHBH025(T) shutter only and should not be used to control shutters of different sizes. For more details on the SC22 shutter controller, please see the SC22 Controller tab above.

We also offer the SC30 benchtop shutter controller (sold separately below), which can be used with our Ø1/4", Ø1/2", and Ø1" diaphragm shutters, as well as our Ø1/2" and Ø1" motorized single-blade shutters. When used with Thorlabs shutters, the operating frequency and timing performance of the SC30 controller is determined by the specific requirements of the selected shutter. Up to two SHB Series shutters can be controlled by hand using the buttons on the front of the unit, by BNC input for external triggering, BNC output for synchronization with other equipment, or by USB 2.0 Type-B (USB 2.0 Type-A to Type-B cable included) for remote computer control using the included standalone software GUI. For information on controller specifications, please see the Specs tab. To download the SC30 controller software, see the SC30 Software tab.

Third party controllers should not be used to control this shutter.

Mounting Adapter
A mounting adapter for these shutters is available separately below. The mounting adapter includes an 8-32 (M4 x 0.7) tap for mounting onto Ø1/2" post assemblies and through holes to attach cage rods for integration into 30 mm cage systems.

Diaphragm Shutters Selection Guide
Item #	SHBH025	SHBH025T	SHBH05	SHBH05T	SHBH1	SHBH1T
Shutter Photo (Click to Enlarge)
Aperture Size	Ø0.25" (Ø6.4 mm)		Ø0.508" (Ø12.90 mm)		Ø1.00" (Ø25.4 mm)
Outer Diameter	Ø1.00" (Ø25.4 mm)		Ø1.10" (Ø27.9 mm)		Ø2.25" (Ø57.2 mm)
Blade Coating	Uncoated	PTFE	Uncoated	PTFE	Uncoated	PTFE
Operating Frequency	0 - 50 Hz		0 - 25 Hz		0 - 15 Hz
Minimum Exposure Pulse	10 ms Typ., 12 ms Max^a,b		29 ms Typ., 31 ms Max^b,c		28 ms Typ., 30 ms Max^b,d
Typical Open / Close Time	3 ms / 3 ms		8 ms / 9 ms		10 ms / 9 ms
Compatible Mounting Adapters	SHCP025(/M)		SHCP05(/M) and SHM05(/M)		SHM1(/M) and SHC1

Measured from 50% open to 50% closed using SC22 controller to provide the minimum drive pulse (MDP) of 10 ms.
See B - F in the Shutter Timing diagram on the Specs tab for more information.
Measured from 50% open to 50% closed using SC21 controller to provide the minimum drive pulse (MDP) of 29 ms.
Measured from 50% open to 50% closed using SC20 controller to provide the minimum drive pulse (MDP) of 25 ms.

Table 2.1 Shutter Specifications^a
Item #s		SHBH025(T)
Electrical Specifications
Coil Resistance		8.2 Ω ± 2.5%
Shutter Drive Voltage		7.0 VDC (Typical) 8.0 VDC (Max)
Controller Drive Type		Pulse Width Modulation at 20 kHz
Hall Effect Sensor Supply Voltage		+5 VDC
Hall Effect Sensor Feedback Signal		Shutter Closed: High (4.89 V Typ.) Shutter Open: Low (0.11 V Typ.)
Performance Specifications
Operating Temperature		15 - 40 °C
Operating Frequency Range		0 - 50 Hz
Max Operating Duration	0 - 15 Hz	Continuous^b
Max Operating Duration	16 - 50 Hz	1 Minute
Typical Lifetime		5 Million Cycles
Key Timings		Typical	Max
Minimum Exposure Pulse^c		10 ms	12 ms
Rise (Open) Time^d		3 ms	4 ms
Fall (Close) Time^d		3 ms	4 ms
Exposure Accuracy^e		2 ± 0.5 ms
Jitter (Rising or Falling Edge)	≤10 Hz	1.8 ms	4 ms
Jitter (Rising or Falling Edge)	11 to 15 Hz	3.5 ms	8 ms
Exposure Repeatability Jitter^f		<4 ms
Mechanical Specifications
Aperture Diameter		0.25" (6.4 mm)
Boxed Weight		0.4 lbs (0.2 kg)
Number of Blades		2
Blade Finish		SHBH025: Polished Stainless Steel SHBH025T: PTFE Coated

Unless otherwise indicated, all specifications were measured at 25 °C. The shutter blade for Item # ending in 'T' has an anti-reflective PTFE coating. For reflectance data, as well as typical jitter performance over the lifetime of a shutter, please see the Graphs tab.
Shutter can get very hot if used outside of heat-sinking mount, allow 5 minutes to cool before handling.
Measured from 50% open to 50% closed using SC22 controller to provide the minimum drive pulse (MDP) of 10 ms. See Table 2.4 and Figure 2.3 for more information.
Measured from 0% to 100% for Rise Time and 100% to 0% for Fall Time.
Referenced to the external input drive pulse over a range of 4 to 15 Hz using the SC22 controller.
Measured 50 times repeatedly over a range of 4 to 15 Hz using the SC22 controller.

Table 2.2 Controller Specifications
Item #	SC22^a	SC30^b
Electrical Specifications (Shutter Drive)
External Modulation Input Voltage, TTL	Low: 0 to 0.8 VDC High: 2.0 to 5.0 VDC	Low: 0 to 0.5 VDC High: 2.0 to 5.0 VDC
Shutter Drive Voltage	7.0 VDC (Typical) 8.0 VDC (Max)	7.0 V Pulse (SHB Series Shutters) 24.0 V Pulse (SH Series Shutters)
Controller Drive Type	Pulse Width Modulation at 20 kHz	Pulse Width Modulation at 22 kHz
Performance Specifications
Operating Temperature	15 - 40 °C	10 - 40 °C
Operating Frequency Range	0 - 50 Hz	0 - 50 Hz
Mechanical Specifications
Boxed Weight	1.8 lbs (0.8 kg)	3.35 lbs (1.5 kg)^c
Electrical Specifications
AC Line Voltage, Frequency	100 - 240 V, 47 - 63 Hz	100 - 240 V, 50 - 60 Hz
AC Current	0.4 A	N/A
DC Voltage	5.0 VDC @ 2.4 A	N/A
Interlock Output Specifications
Operating Voltage	12 VDC (Max)	5 VDC (Max)
Current	1 A (Max)	N/A
Mating Connector	2.5 mm Mono Phono Jack

Unless otherwise indicated, all specifications were measured at 25 °C.
These are general specifications of the SC30 controller. When used with Thorlabs shutters, the operating frequency and timing performance of the controller are determined by the specific requirements of the selected shutter.
Weight of just the controller console.

Click to Enlarge
Figure 2.3 Shutter Timing Diagram. Refer to Table 2.4 for details.

Table 2.4 Shutter Timing Specifications
Diagram Key^a	Description	SHBH025(T)
Diagram Key^a	Description	Typical	Max
I - A	Delay between input pulse rising edge and initialization of shutter opening	3.3 ms	4 ms
A - C	Rising edge to 100% open	3.4 ms	4 ms
I - C	Delay from input pulse rising edge to shutter being fully open	6.7 ms	7.5 ms
D - E	Delay from fall of input pulse to initialization of shutter closing	2.6 ms	3.5 ms
E - G	Falling Edge to 100% closed	3 ms	4 ms
D - G	Delay from fall of input pulse to shutter being fully closed	6 ms	7 ms
I - D^b	Minimum Drive Pulse (MDP)	10 ms	12 ms
C - E^b	Minimum exposure pulse at the top of the pulse	7.6 ms	8 ms
B - F^b	Minimum exposure pulse at 50% of the pulse	10 ms	12 ms
A - G^b	Minimum Exposure Pulse at the bottom of the pulse	14 ms	15 ms

The letters refer to the points shown in the diagram to the left.
These measurements use the MDP, which is the minimum pulse to drive the minimum open time (I - D).

Click to Enlarge
Click Here for Data
Typical Jitter Stability of an SHBH025 Shutter. This plot applies to both SHBH025 and SHBH025T shutters.

Click to Enlarge
Click Here for Data
The plot above gives the typical reflectance for the PTFE coating deposited
on both sides of the shutter blades of Item # SHBH025T. This data is not guaranteed and should be used only as a reference.

Click to Enlarge
Figure 4.2 SC22 Shutter Controller Back

Click to Enlarge
Figure 4.1 SC22 Shutter Controller Front

Shutter Controller

These diaphragm shutters can be driven using the SC22 controller, which is capable of operating in two modulation modes: manual or external. In addition, when in external modulation mode, the shutter may be run in either protected or unprotected mode; in unprotected mode the over-temperature shut down is disabled. Descriptions of each of these modes, as well as the LED indicators displayed in each mode, are given below. For convenience, this information is detailed in the manual provided with the shutter and summarized on a quick reference guide on the bottom of the controller.

Manual Modulation Mode

The shutter can be controlled manually by pressing the ENABLE button on the top of the controller. If the shutter is closed, pressing the enable button once will open the shutter and turn the status LED green. Pressing the enable button again will close the shutter and the status LED will turn off. If the blades become jammed, the shutter will stop operating, the status LED will turn red, and the interlock circuit will open.

External Modulation Modes

The shutter may also be controlled with an external 0 - 5 V TTL signal by connecting a TTL source and then powering on the controller. If the shutter does not begin operating, press and hold the enable button to enter external modulation mode. There are two external modulation modes, Protected and Unprotected, which are described below. If the blades become jammed while operating the shutter in either external modulation mode, the shutter will stop operating, the status LED will turn red, and the interlock circuit will open.

Protected Mode
In protected mode, the shutter can operate at frequencies between the max protected and unprotected continuous frequencies for limited periods of time (bursts). The shutter will shut down if run for too long at these frequencies to protect the unit from overheating. The temperature is not monitored directly, but rather a time limit based on operating the shutter at room temperature without cooling is used. For details on these time limits, please see the Specs tab. The status LED will turn green when the shutter is open and will turn off when the shutter is closed.

Unprotected Mode
In unprotected mode, the shutter will continue to operate at frequencies between the max protected and unprotected continuous frequencies even if the time limit specified for the protected mode is exceeded. This mode is designed for users who actively mitigate the heat within a system containing the shutter. Please carefully note the values on the Specs tab for operating conditions, and be aware that operating in the unprotected mode may lead to shutter damage. The status LED will turn amber when the shutter is open and will turn off when the shutter is closed.

Change Mode to

	Manual	External Protected	External Unprotected
Manual	-	Hold ENABLE button for 3 seconds.	Hold POWER and ENABLE buttons for 3 seconds.
External Protected	Press ENABLE button.	-	Hold POWER and ENABLE buttons for 3 seconds.
External Unprotected	Press ENABLE button.	Hold POWER and ENABLE buttons for 3 seconds.	-

LED Status Indicator
Mode \ LED State	Shutter Closed	Shutter Open	Over- Temperature Warning	Over- Temperature	Max Frequency Exceeded	Blade Jammed
Manual	^a		Not Applicable	Not Applicable	Not Applicable
External Protected	^a		^b
External Unprotected	^a		^c

The LED is off.
The LED will turn amber 15 seconds prior to shut down. It will no longer turn on and off as shutter opens and closes.
The LED will turn amber 15 seconds prior to when shut down would occur in Protected Mode. However, in Unprotected Mode, the unit will not shut down.

Software for the SC30 Shutter Controller

Software

Version 1.0.0 (March 21, 2025)

Standard full software application packages and graphical user interfaces.

Figure 5.1 SC30 Software GUI Screen

Thorlabs offers the SC30 software package as a way to operate our SC30 Benchtop Shutter Controller and includes a GUI, drivers, and LabVIEW™/C++ SDK for secondary development. The software can be used to control the timing of open and close sequences for SH and SHB series shutters connected to the SC30 controller.

This software features .NET controls which can be used by 3rd party developers working in the latest C#, Visual Basic, LabVIEW™, or any .NET compatible languages to create custom applications. Low-level DLL libraries are included for applications not expected to use the .NET framework and APIs are included with each install.

SHBH025 and SC22 Pin Diagrams

4-Pin Mini-DIN Shutter Interface Connector
Pin	Description
1	Shutter Detect
2	Modulation +
3	+5 VDC
4	Modulation -
Shield	GND

External Modulation Input: TTL 0 to 5 V, Female BNC

Interlock Output: 2.5 mm Mono Phone Jack

Figure 6.2 Female Jack on SC22 Controller

Figure 6.1 Male Plug on 35" (889 mm) Long Shutter Cord

SC30 Pin Diagrams

SH Series Interface Connector

HR10-7R-6S

6 Pin HRS Connector

Pin	Description
1	To Opto Anode (12 V limited to 20 mA)
2	To Shutter Coil - 24 V Pulse - 10 V Steady State (0.4 A max)
3	To Shutter Coil - GND (on) - Open Circuit (off)
4	To Opto Cathode - GND
5	To Opto Emitter - GND
6	To Opto Collector (2.5V)

SHB Series Interface Connector

4-Pin Mini-DIN

Pin	Description
1	Shutter Detect
2	Modulation +
3	+5 VDC
4	Modulation -
Shield	GND

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Ø1/4" Diaphragm Shutters

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Key Specifications^a
Item #s	SHBH025	SHBH025(T)
Operating Frequency	0 - 50 Hz
Minimum Exposure Pulse^b (Typical)	10 ms
Open Time (Typical)	3 ms
Close Time (Typical)	3 ms
Mechanical Drawing (Click for Details)
PTFE Coating Reflectance (Click for Graph)	N/A	Raw Data

Refer to the Specs tab for complete specifications.
Measured from 50% open to 50% closed using SC22 controller to provide the minimum drive pulse (MDP) of 10 ms.

Two Stainless Steel Blades:
- SHBH025: Uncoated Stainless Steel Blades
- SHBH025T: PTFE-Coated Stainless Steel Blades for Low Reflectance
Shutter Housing Dimensions: Ø1.00", 0.29" Thick
Adapter Available for Cage and Post Compatibility (Sold Separately Below)

Thorlabs' SHBH025 and SHBH025T diaphragm shutters have two stainless steel leaves and a Ø1/4" aperture in a compact, Ø1.00", 0.29" thick housing. The leaves of the SHBH025 shutter are uncoated, while the leaves of the SHB025T shutter are coated with PTFE for low reflectance. Each shutter requires a controller (sold separately below). Each shutter has a 35" cable with a 4-pin mini-DIN male connector to connect the shutter to a SC22 or SC30 controller. For information on controller specifications, please see the Specs tab.

Two Ø0.06" (Ø1.6 mm) through holes are provided around the edge of the housing that can accept #0 (M1.4) screws for custom and OEM mounting options. Only use non-magnetic screws; using magnetic screws may degrade shutter performance. To mount these shutters on our selection of posts or integrate them into a 30 mm cage system, we offer the SHCP025(/M) Mounting Adapter, available below.

Ø1/4" Diaphragm Shutter Controller

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Compatible with Thorlabs' Ø1/4" Diaphragm Optical Beam Shutters
Operates in Manual or External Modulation Modes
15 to 40 °C Operating Range
Power Supply Included

The SC22 compact controller offers a simple interface for operating the 1/4" diaphragm optical beam shutters. Power and Status LEDs indicate the shutter state, a BNC connector accepts an external TTL signal, and a 2.5 mm mono jack interlock output is provided. The 2.5 mm mono plug is not included but is available upon request. The controller has a compact 3.00" x 3.50" x 1.38" housing. The SC22 controller has a 4-pin mini-DIN shielded female shutter interface connector. A universal power supply for 100 - 240 VAC, 47 - 63 Hz is provided, along with a location-specific AC power cord. For more details on the shutter controller, please see the SC22 Controller tab above.

Third party controllers should not be used to control these shutters. This controller is programmed for use with the Ø1/4" Diaphragm Shutters above and should not be used with other shutter types or sizes.

Benchtop Optical Shutter Controller

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Compatible with SH and SHB Series Shutters
Local Operation or Remote Control via LabVIEW™, LabWindows™, USB, or BNC
Programmable with Repeating Open/Close Sequences at Millisecond Intervals
LCD Front Panel with Dedicated Shutter Status Indicators
Safety Alarm When Coupled with Thorlabs Beam Shutters

Thorlabs' SC30 Shutter Controller provides an easy-to-use control interface for our SH and SHB Series Optical Shutters. Up to two shutters can be controlled by hand using the buttons on the front of the unit, by BNC input for external triggering, BNC output for synchronization with other equipment, or by USB 2.0 Type-B (USB 2.0 Type-A to Type-B cable included) for remote computer control. The display on the front panel reveals if each shutter is enabled and if the shutter is open. It also features a lock/unlock button that disables or enables opening of the shutter, helping to comply with lab laser safety requirements. If enabled in the settings, it also incorporates a rear panel safety interlock via a 2.5 mm mono phone jack that overrides all system commands and closes the shutter. If the interlock is tripped, the lock/unlock must be cycled to resume operations.

The easy-to-read LCD front panel provides access to the same commands as the included LabVIEW and LabWindows software packages. In addition to simply opening or closing the shutter, a repeating sequence of open and close events with exposure times as low as 10 ms can be set up and initiated either by a front panel button, a TTL pulse (+5 V), or a computer command via USB. Alternatively, the shutter can be synchronized to follow the rising and falling edges of an external voltage supplied over BNC.

The optical shutter controller includes LabVIEW VI's suitable for integrating into existing LabVIEW applications. A standalone executable written in LabWindows/CVI is also provided, allowing remote computer control of the SC30 without any additional programming. See the SC30 Software tab to download these packages.

The shutter controller's BNC output allows it to double as a standalone digital delay generator with 1 ms resolution and 0.1 ms accuracy.

Mounting Adapter for Ø1/4" Diaphragm Shutters

Mounting Adapter for Ø1/4in Diaphragm Shutters

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Click to Enlarge
Figure G4.2 The adapter allows the SHBH025 shutter to be mounted within a 30 mm cage system.

Click to Enlarge
Figure G4.1 The double bore of the SHCP025 accepts the outer diameter of the shutter.

8-32 (M4 x 0.7) Tap for Mounting on a Ø1/2" Post
Four Cage Rod Through Holes for Mounting Within a 30 mm Cage System
Shutter Secured Using Top-Located 8-32 (5/64" [2.0 mm] Hex) Nylon-Tipped Setscrew
Compact Design: 0.35" Thick

The SHCP025(/M) Mounting Adapter is designed to make our Ø1/4" diaphragm shutters compatible with Ø1/2" posts and 30 mm cage systems. The adapter features a double bore that accepts the outer diameter of the shutter and a notch allows its cord to pass freely, as shown in the photograph to the right. The top of the adapter has an 8-32 (5/64" [2.0 mm] hex) nylon-tipped setscrew for securing the shutter, which mounts with three points of contact.

The adapter allows the shutter to be placed anywhere within a 30 mm cage system by providing four through holes for use with Ø6 mm cage rods. Four side-located 8-32 (5/64" [2.0 mm] hex) setscrews secure the cage rods. A Ø1/2" post can be attached to the bottom of the adapter using the 8-32 (M4) tapped hole.