Photodiode Étienne

These photodiodes were developed by Étienne in cooperation with the AEI and altered to peak at about 16.2MHz.

Schematics Used

Schematic

Interactive Schematic

HAMAMATSU S5971: Photodiode @ 960NM, 100MHz

Notable Changes Made

To achieve a peak at around 16.2MHz, components had to be changed.
Changed components:

Schematic Component	Used Component
L1	6u8	6u8
C3	6p	2 x 4.7p
R2	40.2R	40.2R
Changed only for the 3rd and 4th build
U5	AD587	LT1236A-10
C19	1u	none

For Coil L1 the part 1812CS-682XJLC (or at least a part with the same form factor) has to be used

C3 influences at which frequency the peak will be

Instead of the AD587, LT1236A-10 can be used

When doing this, the C19 component must not be soldered.

C19 connects pin 8 of U5 to ground. Pin 8 is not in use in LT1236A-10.

Using The Photodiode

The photodiode requires a power input of +/- 15V

AC Output: right SMA connector

DC Output: left SMA connector

When using a spectrum-analyzer (e.g. RIGOL DSA815) in combination with the ROHDE&SCHWARZ signal-generator, a 50Ω terminator must be used, too

Measured Data

The traces of the amplitude and phase were measured.

A <fc #ff0000>RIGOL Network Analyzer</fc> was used to gather that data from the AC output

A 9V test-laser with a modulation of -10dB @ 100MHz was used in this experimental setup

The traces of the diodes were fitted in Python

The results:

Diode	Resonance frequency [MHz]	Peak to 15MHz Ratio [dB]	P14R [dB]	P17R [dB]	P18R [dB]	FWHM with Gauß-Fit [kHz]	Phase #1	Comment
1	16.11 [+/- 0.015]	8.65	13.71	6.99	12.44	271.75
2	16.14 [+/- 0.01]	8.92	13.46	6.53	11.34	270.98
3	16.13 [+/- 0.01]	9.17	14.75	6.66	12.13	271.45
4	16.16 [+/- 0.01]	9.39	14.81	6.5	12.09	269.72

#1

X = MAx dazu Y Wert = Peak hight over ..

<fc #ff0000>Es feht der Fehler von der Linienbreite und des Max Peaks</fc>

Höhe des Resonanz-Peaks über Rauschen

FWHM [Diode 1]: 271750.86662876786Hz
FWHM [Diode 2]: 270984.2391765082Hz
FWHM [Diode 3]: 271450.8282159102Hz
FWHM [Diode 4]: 269724.22527546244Hz