VFC1-JCAA - Voxtel

Deschutes BSI 

VFC-1000 Series 

Packaged APD 

DESCHUTES BSI APD Products 

Reduced-noise Avalanche Photodiode (R-APD) in hermetic 

packages with optional 3-stage TE cooler 

Features 

▪ Hermetically packaged reduced-noise 

NIR InGaAs avalanche 

photodiode (R-APD) 

▪ 75µm and 200µm diameters 

▪ Low k eff ~0.20, resulting in 

low excess noise 

▪ 950-1700nm spectral response 

▪ 

Superior sensitivity not 

achieved with contemporary 

APDs 

▪ TO-46/TO-8 packaging options 

include a broadband, doubleside 

AR-coated flat window 

and 3-stage TE cooler 

Applications 

▪ Free-space optical 

communications 

▪ Laser range finding 

▪ Optical time domain reflectometry 

▪ Optical coherence tomography 

▪ Fluorescence measurements, 

spectroscopy, chromatography 

and electrophoresis 

▪ Replacement for photomultiplier 

tubes 

Model VFC1-xCAA, VFC1-xKAB Packaged APDs 

Reduced excess noise APDs (R-APDs) in hermetic TO-46 (VFC1-xCAA 

series) or TO-8 (VFC1-xKAB series) packages allow users to easily integrate 

Voxtel's 950–1700nm response APDs into high-performance 

electro-optical systems. The TO-8 packages allows for a 3-stage 

thermo-electric(TE) cooler which can provide 100°C temperature 

differential from ambient (packages rated down to -40°C.) 

Voxtel’s VFI-1000 R-APDs are designed to deliver the best possible 

sensitivity for high-bandwidth near infrared (NIR) and short-wavelength 

infrared (SWIR) optical applications. With low avalanche noise 

and high quantum efficiency over the 950–1700nm spectral band, 

including the eye-safe wavelengths above 1400nm, the VFC-1000 In- 

GaAs R-APDs provide enhanced responsivity relative to p-i-n photodiodes, 

with lower noise than conventional NIR APD designs. 

Voxtel’s thin InAlAs multiplication region InGaAs APD technology suppresses 

the excess multiplication noise associated with the avalanche 

process, improving the signal-to-noise ratio of the detector. Contemporary 

APDs achieve high responsivity through internal current gain, 

but the usefulness of the gain of these APDs is undermined by the accompanying 

noise. Voxtel’s R-APDs can be operated at relatively high 

gain with a smaller noise penalty, providing a significant advantage. 

Coupling the R-APD to a low-noise amplifier produces a receiver with 

superior noise equivalent power (sensitivity). 

Voxtel, Inc., 15985 NW Schendel Avenue, #200, Beaverton, OR 97006, www.voxtel-inc.com, T 971.223.5646, F 503.296.2862 

Voxtel Literature No. VFC1-xCAA / xKAB, Version date: 06/2012 © 

Voxtel makes no warranty or representation regarding its products’ specific application suitability and may make changes to the products described without notice.

Packaged APD 

Deschutes BSI 


D e s c h u t e s B S I S e r i e s P a c k a g e d A P D s 

M O D E L V F C 1 - x C C A / x K A B 

2 

Responsivity [A/W] 

1 

0.8 

0.6 

0.4 

0.2 

0.0 

Deschutes BSI Responsivity 

Deschutes BSI QE 

900 1100 1300 1500 1700 

Wavelength [nm] 

Spectral responsivity and quantum efficiency 

of 200µm APD @ 298K 

100 

80 

60 

40 

20 

0 

Excess Noise Factor (F) 

5 

4.5 

4 

3.5 

3 

2.5 

2 

1.5 

1 

k=0.4 (Telecom APD) 

k=0.2 

Deschutes BSI R-APD 

0 1 2 3 4 5 6 7 8 9 10 11 12 

Gain (M) 

Excess noise of the Deschutes BSI R-APD, k~0.2 

47.50 

M=10 Dark Current [A] 

1.E-07 

1.E-08 

1.E-09 

I dark = 6x10 15 e 0.05T 

R 2 = 0.994 

Breakdown Voltage (V) 

47.00 

46.50 

46.00 

45.50 

45.00 

44.50 

44.00 

43.50 

V br = 0.34T+36.1 

R 2 = 0.999 

43.00 

1.E-10 

200.00 250.00 300.00 350.00 

Temperature [K] 

42.50 

200.00 250.00 300.00 350.00 

Temperature [K] 

Effects of temperature on dark current and breakdown voltage of 

a 200µm Deschutes BSI R-APD at M=10 




Deschutes BSI 


Packaged APD 

M O D E L V F C 1 - x C C A 

Mechanical Information 

M e c h a n i c a l I n f o r m a t i o n 

D e s c h u t e s B S I S e r i e s P a c k a g e d A P D s 

TO-46 Package 

.118 

.114 

.012 

.009 

.046 

.042 

.010 max. 

.072 in 

183 mm 

Ø .026 

Ø .020 

.700 

.500 

.010 

.007 

.006 

.000 

3 

Ø .100 

Ø .212 

Ø .209 

Ø .171 

Ø .161 

4 

2 

1 

Ø .048 

Ø .046 

.043 

.031 

.045 

.037 

Pinout 

1) APD Cathode 

2) APD Anode 

3) Ground, T Sense – 

4) T Sense + 

3 

Ø .019 

Ø .016 

45° ± 0.5° 

SIDE VIEW 

with cap 

TOP VIEW 

header only 

TO-8 Package 

7.16 mm 

APD Plane 

Ø 0.46 

2.24 ± 0.31 

0.79 

1 4 

0.79 

Active area Ø 1.52 

12 11 10 9 

5.38 

25.40 ± 0.64 

1.91 

9.91 

2.87 

5.72 

Ø 15.24 

9.53 

Pinout 

1) TEC – 

4) TEC + 

9) Temp Sense – 

10) Temp Sense + 

11) APD Anode (P) 

12) APD Cathode (N) 




Packaged APD 

Deschutes BSI 


M O D E L V F C 1 - J C A A ( T O - 4 6 ) 

M O D E L V F C 1 - J K A B 

( T O - 8 w/ 3 - s t a g e T E C ) 

V F C - 1 0 0 0 S e r i e s P a c k a g e d A P D s 

7 5 - m i c r o n , 2 . 0 G H z R - A P D 

Specifications 

Parameter Min Typical Max Units 

Spectral Range, λ 950 1000–1600 1750 nm 

Active Diameter 75 μm 

APD Operating Gain, M 1 10 20 

4 

Responsivity at M=1 

Excess Noise Factor, F(M,k) 

.66 

.91 

.73 

1.01 

3.4 

4.3 

.78 

1.04 

A / W 

λ=1064nm 

λ=1550nm 

M=10 

M=15 

Noise Spectral Density @ M=10 0.48 pA / Hz 1/2 

Dark Current @ M=1 i 0.8 1.9 2.5 nA 

Total Capacitance ii 0.76 pF 

Bandwidth 2.0 GHz 

Breakdown Voltage, V BR 

iii 

44 49 55 V 

∆V BR /∆T 30 34 39 mV / K 

Minimum Internal Temperature -40 °C 

TE cooler rating iv 1.9 / 1.2 V / A 

Temperature Sensing Diode 

Voltage and ΔV/K v 0.48 

0.50 

-2.18mV / K 

0.51 V 

Maximum Instantaneous 

1 mW 

Input Power vi 

i 

G a i n n o r m a l i z e d f r o m M=10, T = 2 9 8 K 

i i 

M>3 

i i i 

T=298K; I dark > 0 . 1 m A 

i v F o r V F C 1 - x K A B d e v i c e s , p a c k a g e a t 2 9 8 K 

v 

S o u r c i n g 1 0 μ A , T = 2 9 8 K 

v i 

1 0 n s , 1 0 6 4 n m s i g n a l a t a 2 0 H z P R F 

w i t h a n A P D m u l t i p l i c a t i o n g a i n o f M=10 




Deschutes BSI 


Packaged APD 

M O D E L V F C 1 - N C A A ( T O - 4 6 ) 

M O D E L V F C 1 - N K A B 

( T O - 8 w/ 3 - s t a g e T E C ) 


2 0 0 - m i c r o n , 5 0 0 M H z R - A P D 








.66 

.91 

.73 

1.01 

3.9 

7.9 

.78 

1.04 

A / W 

λ=1064nm 

λ=1550nm 

M=10 

M=20 


Dark Current @ M=1 i 6 8.1 10.0 nA 


Bandwidth 500 MHz 


iii 

44 49 55 V 

∆V BR /∆T 30 34 39 mV / K 





0.50 

-2.18mV / K 

0.51 V 


5 mW 


5 

i 


i i 

M>3 

i i i 

T=298K; I dark > 0 . 1 m A 


v 

S o u r c i n g 1 0 μ A , T = 2 9 8 K 

v i 






Packaged APD 

Deschutes BSI 


M O D E L V F C 1 - P K A B 

( T O - 8 w/s - s t a g e T E C ) 


5 0 0 - m i c r o n , 1 0 0 M H z R - A P D 






6 



.66 

.91 

.73 

1.01 

3.9 

7.9 

.78 

1.04 

A / W 

λ=1064nm 

λ=1550nm 

M=10 

M=20 


Dark Current @ M=1 i 40 60 90 nA 


Bandwidth 90 100 200 MHz 


iii 

44 49 55 V 

∆V BR /∆T 30 34 39 mV / K 





0.50 

-2.18mV / K 

0.51 V 


20 mW 


i 


i i 

M>3 

i i i 

T=298K; I dark > 0 . 1 m A 


v 

S o u r c i n g 1 0 μ A , T = 2 9 8 K 

v i 






Deschutes BSI 


Packaged APD 

O r d e r i n g I n f o r m a t i o n F o r V F C - 1 0 0 0 S e r i e s A P D P r o d u c t s 

V F C 1 - - A - 

Device Device Type Detector Diameter Package Window Revision 

V=APD F=Linear mode C=Deschutes 1=Single 

BSI R-APD Element 

J=75µm 

N=200µm 

P=500µm 

C=TO- 46 

K=TO-8 w/3-stage 

TE-Cooler 

A=Flat 

Not all combinations of product features are available. Please contact 

Voxtel for specific ordering information and parts availability. 

7 

C a u t i o n D u r i n g A P D O p e r a t i o n 

If an APD is operated above its breakdown voltage 

without some form of current protection, it can draw 

enough current to destroy itself. To guard against 

this, the user can add either a protective resistor 

to the bias circuit or a current-limiting circuit in the 

supporting electronics. 

The breakdown voltage of an APD is dependent 

upon its temperature: the breakdown voltage decreases 

when the APD is cooled. Consequently, a reverse 

bias operating point that is safe at room temperature 

may put the APD into breakdown at low 

temperature. The approximate temperature dependence 

of the breakdown voltage is published in the 

spec sheet for the part, but caution should be exercised 

when an APD is cooled. 

Low-noise readout circuits usually have high impedance, 

and an unusually strong current pulse from 

the APD could generate a momentary excessive voltage 

that is higher than the readout’s supply voltage, 

possibly damaging the input to the amplifier. To prevent 

this, a protective circuit should be connected 

to divert excessive voltage at the inputs to a power 

supply voltage line. 

As noted in the specification, another consideration 

is that the APD gain changes depending on 

temperature. When an APD is used over a wide temperature 

range, it is necessary to use some kind 

of temperature compensation to obtain operation at 

a stable gain. This can be implemented as either 

regulation of the applied reverse bias according to 

temperature, feedback temperature control using a 

thermoelectric cooler (TEC) or other refrigerator, or 

both. 

Upon request, Voxtel will gladly assist customers 

in implementing the proper controls to ensure safe 

and reliable operation of APDs in their system.

VFC1-JCAA - Voxtel

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