JPS58111390A - Laser diode with light-receiving element - Google Patents

Abstract

PURPOSE:To design a circuit easily while accurately detecting the temperature of a flange by forming each electrode of the element as independent external electrodes. CONSTITUTION:Two electrodes of a laser diode element 4 and two electrodes of the light-receiving element 6 are extracted as independent external terminals by using leads 28-30 and a package 12. The light-receiving element 6 is formed in structure in which an intrinsic region 22 and a P conduction type region 23 are shaped into an N conduction type island region 21 formed at the center of the upper surface of a P conduction type substrate 20 in succession. Accordingly, since a P-N junction 24 for insulating the light-receiving element 6 functions as an insulator during operation, the electrodes of each element have the independent external terminals, thus resulting in easy incorporation into circuits of various kinds.

Description

[Detailed description of the invention] The present invention relates to a receiver diode with a bulky element.

A laser diode, which detects the intensity f of laser light with a light receiving element (photodiode), has a structure as shown in FIG. That is, a stem 2 made of a metal with good thermal conductivity is vertically disposed on the upper surface Kti of the seven flange 1 made of a metal with good thermal conductivity. A laser diode element 4 is fixed via the upper end of the stem 2 (submount 3t). The laser diode element 4 emits laser light 5 in the vertical direction from the upper and lower end faces, respectively.

A photodiode element (light receiving element) 6 is fixed to a portion of the flange 1 where the laser beam 5 traveling downward reaches, and monitors the light intensity of the laser beam 5. Further, twelve leads 7.8 are fixed to the seven flange 1 through an insulator. These two leads7.
One end of a wire 9.10, which is separately connected to the laser diode element 4 and one electrode of the receiver 6, is connected to the upper end of the wire 8. In addition, the laser diode element 4
The other electrodes of the element 6 are connected to the 7 flange 1. As a result, this laser diode with a light receiving element constitutes a circuit having three external S terminals as shown in FIG. In addition, in the figure, 4 is a laser diode element, and 6 is a laser diode element.
Ki Ukemoto Yuiko Demeru. Furthermore, this receiver jt and the laser diode with element are constructed by placing a metal cap 11 on the flange l, and fixing each element to the flange 1 by a small amount to form a package 121. A glass plate 13 is attached to the ceiling 11 of the cap 11 to form a window 14Yt through which the radar beam 5 is emitted.

By the way, when such a laser diode with a light receiving element is incorporated into the automatic gain control 11111, since one electrode of the light receiving element 6 is directly connected to the ground, the 3rd m! As shown in GK, when using an OF amplifier, a current-voltage conversion circuit consisting of an amplifier 1B and a resistor 16.17 is required at the first stage of the negative path, or when using a polarity polarity OP amplifier As shown by 4111, it is necessary to connect two Zener diodes 18 and 19 in series and maintain a constant INK of the electrode of the common external terminal, which causes inconvenience in terms of circuit design. In addition, when using the latter Zener diode,
The voltage of each Zener diode is not constant and the potential is R.

Therefore, it is conceivable to electrically separate the laser diode element or the submount 1IT or the flange-operating electrode from the 7 flange so that each electrode is drawn out as an erect outer S spiral.

In this case, a connection between the flange and the element is provided, but the laser diode element emits a large amount of heat and is extremely sensitive to temperature (-2mV/C).
) Therefore, the insulation s17 having poor heat conductivity (in other words, heat dissipation) cannot be interposed in the laser diode element. An insulator is interposed between the light receiving element and the receiving element, and two electrodes are provided on the upper surface of the receiving element, each of which is connected to a lead via a wire.

On the other hand, as a mechanism for more accurately correcting the intensity of the laser source while monitoring the flange m degrees, a structure in which a Q1 star element is attached to the 7 flange can be considered. However, since the thermistor element uses glass as a package material, it has poor thermal conductivity, and there is a time delay in detecting the seven-range temperature drop. (This can be done by controlling the voltage applied.) becomes inaccurate.

On the other hand, it is known that the forward voltage (V) of the PliQ layer of silicon is low.

Therefore, when considering detecting the temperature of 7 ranges by monitoring the forward voltage of p y@@- of the light receiving element, as described above (via the light receiving element and an insulating film with poor thermal conductivity), Even if the structure is fixed to a straw sill, the 7 lunge degree detection will not be accurate.

Therefore, the purpose of this invention is to eliminate the inconvenience in terms of circuit design by making each electrode of the element an independent external electrode, and to solve the problem of 7-range S [with a light-receiving element structure that allows accurate detection]. Our goal is to provide laser diodes.

In order to achieve this purpose, I! j1 is a laser diode having a light receiving element for monitoring the laser source tube, and it can be drawn out as an independent external terminal using only the two electrodes of the laser diode element and the two electrodes of the light receiving element and the package case or lead. Toto 4K
The light-receiving element is electrically insulated and connected to the 7-pin through the PMil board, and hereinafter the present invention will be described from Example NK to TVLa. FIG. 5 is a cross-sectional view of a laser diode with a light-receiving element according to one embodiment of the present invention j1gN, and figure #16 is a cross-section of the light-receiving element 11! J, jl! FIG. 7 is a circuit diagram in which a resistor p is attached to the laser diode with a light receiving element and ff7 is in the same state. As shown in Fig. 5, this diode with a receiving element (hereinafter referred to as a laser diode) has a flange l made of a metal with good thermal conductivity on the upper surface of the flange l made of a metal with good thermal conductivity. Stage 5 2l-1i is installed. The upper end of this stem 2 is submacun)C
1, a laser diode element 4 is fixed thereto.

Laser source 5'Ik is emitted in the vertical direction from the upper and lower end surfaces of laser diode element 4Fi. Laser source 5 moving downward
The 7-range IK that the laser beam reaches has a photodiode element (light receiving element) 6 fixed, and the laser source has a power of just over 50 yuan ft-
It is designed to be monitored. As shown in FIG. 6, this light-receiving element 6#'i has a structure in which an intrinsic region 22.degree. It has become. Intrinsic area (1 layer) 221l14muP special turtle type 懺JIIE23
and the shoulder electrodeposited island region 21 formed by the PM to be bonded for the light-receiving element and the shoulder electrodeposited island region 21.
For insulation forming the field E1it (for isolation) P)
The exposed surface of I*&24 is covered by insulation 1125. Further, electrodes 26 and 27 are provided on the surfaces of the M Toden island region 21 and the P conductive layer region 230, respectively. A flange 1Klk is added to the light receiving element 6#i through a gold-silicon composite layer.

On the other hand, three leads 28 to 30 are fixed through the flange IK via an insulator T-. Then, at the upper end of the two wires 21i, 29, the electric field @2B, 21 of the light receiving element 6 is placed.
One end of a wire (guiding wire) 31 and 32 is connected to the other end. Additionally, one end of the remaining board 30 is covered with one end connected to one electrode of the laser diode element number.
The other end of the wire (conductor) 33 is connected to the other end.

The other electrode of the laser diode element 4 is the submount 3
゜It is connected to 7 langes 1 through 2 stems. Also,
This laser diode has a metal cap 1111 on seven flange l, each element is fixed to the flange l by welding, and the cap 11 and flange 1 constitute a package 12. As a result, this laser diode is assembled into a package 12 and three leads 28-30I!, as shown in FIG. Since it has four external terminals consisting of -, the lead-out end 1iFi of each element is independent. Further, a glass plate 13 is attached to the ceiling of the cap 11, forming a window 14 through which the laser beam 5 passes.

In such a laser diode, since the insulating PM contact 24 of the light receiving element 6 acts as an insulating main during operation, the electrode Fi of each element has an independent external terminal.
It can be incorporated into various circuits.

For example, when incorporated into an automatic gain control circuit, a voltage detection type circuit can be formed by incorporating a resistor 34 between the light receiving element 6 and the ground, as shown in Section 7-. This means that A can be held at the desired potential.

Further, in this laser diode, the light receiving element 6 is formed of a silicon plate, and is bonded to the seven flange 1 via a gold-silicon eutectic alloy layer. This kt) 75 engine 1 I
Quickly respond to lK changes. As a result, the light receiving element 60P
By monitoring the change in the forward voltage (V, ) applied to the HQ coupling, it is possible to accurately know the change in the 7 range 1f) iii degree, and the voltage applied to the laser diode element can be more accurately controlled and stabilized. 72: K becomes high enough to oscillate a laser beam of optical intensity.

Note that the present invention is not limited to the above-mentioned actual values, but can be modified based on the technical idea of the present invention. For example, all the lead terminals may be used as leads with t-4 leads.

As described above, according to the present invention, each electrode chamber of the element has independent external electrodes, making it easy to design 5 circuits, and the light-receiving element bone laser has a structure that allows accurate detection of 7-range sat'. Diode t-can be provided.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional laser diode with a light-receiving device, and Figure 2 is an equivalent circuit diagram, as well as Figure 3. Figure 4 is an additional circuit diagram when the automatic gain control circuit is incorporated.
gstg is a @ side view of a laser diode with a light receiving element according to one embodiment of the present invention, FIG. 6 is a cross-sectional view of the same light receiving element, and FIG. It is a circuit diagram. l...7 langes, 2...stem, 3...submount, 4...laser diode element, 6...light receiving element, 12...package, 20...P conductivity type substrate, 21...N conductivity type island region, 22...Intrinsic region, 23...P conductivity type region, 24...Insulating phase PN
Tangent, 2b. 27... Electrode, 28-3o... Lead, 31-33
...wire, 34...resistance. Figure 1 Figure 4 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A laser diode having a light receiving element for monitoring laser ft, which is an independent external am At the same time, the light-receiving element is connected to the 7-lunge in an electrically insulating manner via a P junction.